Replace F extension with string interpolation

OpenRA.Game/Activities/Activity.cs

@@ -95,7 +95,7 @@ namespace OpenRA.Activities
 		public Activity TickOuter(Actor self)
 		{
 			if (State == ActivityState.Done)
-				throw new InvalidOperationException("Actor {0} attempted to tick activity {1} after it had already completed.".F(self, GetType()));
+				throw new InvalidOperationException($"Actor {self} attempted to tick activity {GetType()} after it had already completed.");
 
 			if (State == ActivityState.Queued)
 			{
@@ -105,7 +105,7 @@ namespace OpenRA.Activities
 			}
 
 			if (!firstRunCompleted)
-				throw new InvalidOperationException("Actor {0} attempted to tick activity {1} before running its OnFirstRun method.".F(self, GetType()));
+				throw new InvalidOperationException($"Actor {self} attempted to tick activity {GetType()} before running its OnFirstRun method.");
 
 			// Only run the parent tick when the child is done.
 			// We must always let the child finish on its own before continuing.

OpenRA.Game/Actor.cs

@@ -125,7 +125,7 @@ namespace OpenRA
 				.FirstOrDefault(i => i.Count() > 1);
 
 			if (duplicateInit != null)
-				throw new InvalidDataException("Duplicate initializer '{0}'".F(duplicateInit.Key.Name));
+				throw new InvalidDataException($"Duplicate initializer '{duplicateInit.Key.Name}'");
 
 			var init = new ActorInitializer(this, initDict);
 
@@ -250,7 +250,7 @@ namespace OpenRA
 					continue;
 
 				if (creationActivity != null)
-					throw new InvalidOperationException("More than one enabled ICreationActivity trait: {0} and {1}".F(creationActivity.GetType().Name, ica.GetType().Name));
+					throw new InvalidOperationException($"More than one enabled ICreationActivity trait: {creationActivity.GetType().Name} and {ica.GetType().Name}");
 
 				var activity = ica.GetCreationActivity();
 				if (activity == null)
@@ -592,7 +592,7 @@ namespace OpenRA
 		public int RevokeCondition(int token)
 		{
 			if (!conditionTokens.TryGetValue(token, out var condition))
-				throw new InvalidOperationException("Attempting to revoke condition with invalid token {0} for {1}.".F(token, this));
+				throw new InvalidOperationException($"Attempting to revoke condition with invalid token {token} for {this}.");
 
 			conditionTokens.Remove(token);
 			UpdateConditionState(condition, token, true);
@@ -632,7 +632,7 @@ namespace OpenRA
 
 		public LuaValue ToString(LuaRuntime runtime)
 		{
-			return "Actor ({0})".F(this);
+			return $"Actor ({this})";
 		}
 
 		public bool HasScriptProperty(string name)

OpenRA.Game/CPos.cs

@@ -90,7 +90,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CPos a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CPos.Add(CPos, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CPos.Add(CPos, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -99,7 +99,7 @@ namespace OpenRA
 		{
 			var rightType = right.WrappedClrType();
 			if (!left.TryGetClrValue(out CPos a))
-				throw new LuaException("Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+				throw new LuaException($"Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 
 			if (rightType == typeof(CPos))
 			{
@@ -112,7 +112,7 @@ namespace OpenRA
 				return new LuaCustomClrObject(a - b);
 			}
 
-			throw new LuaException("Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+			throw new LuaException($"Attempted to call CPos.Subtract(CPos, (CPos|CVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 		}
 
 		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)
@@ -132,7 +132,7 @@ namespace OpenRA
 					case "X": return X;
 					case "Y": return Y;
 					case "Layer": return Layer;
-					default: throw new LuaException("CPos does not define a member '{0}'".F(key));
+					default: throw new LuaException($"CPos does not define a member '{key}'");
 				}
 			}
 

OpenRA.Game/CVec.cs

@@ -76,7 +76,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CVec a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CVec.Add(CVec, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CVec.Add(CVec, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -84,7 +84,7 @@ namespace OpenRA
 		public LuaValue Subtract(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out CVec a) || !right.TryGetClrValue(out CVec b))
-				throw new LuaException("Attempted to call CVec.Subtract(CVec, CVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call CVec.Subtract(CVec, CVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a - b);
 		}
@@ -110,7 +110,7 @@ namespace OpenRA
 				{
 					case "X": return X;
 					case "Y": return Y;
-					default: throw new LuaException("CVec does not define a member '{0}'".F(key));
+					default: throw new LuaException($"CVec does not define a member '{key}'");
 				}
 			}
 

OpenRA.Game/Exts.cs

@@ -278,7 +278,7 @@ namespace OpenRA
 		public static int ISqrt(int number, ISqrtRoundMode round = ISqrtRoundMode.Floor)
 		{
 			if (number < 0)
-				throw new InvalidOperationException("Attempted to calculate the square root of a negative integer: {0}".F(number));
+				throw new InvalidOperationException($"Attempted to calculate the square root of a negative integer: {number}");
 
 			return (int)ISqrt((uint)number, round);
 		}
@@ -319,7 +319,7 @@ namespace OpenRA
 		public static long ISqrt(long number, ISqrtRoundMode round = ISqrtRoundMode.Floor)
 		{
 			if (number < 0)
-				throw new InvalidOperationException("Attempted to calculate the square root of a negative integer: {0}".F(number));
+				throw new InvalidOperationException($"Attempted to calculate the square root of a negative integer: {number}");
 
 			return (long)ISqrt((ulong)number, round);
 		}
@@ -429,8 +429,8 @@ namespace OpenRA
 			// If any duplicates were found, throw a descriptive error
 			if (dupKeys.Count > 0)
 			{
-				var badKeysFormatted = string.Join(", ", dupKeys.Select(p => "{0}: [{1}]".F(logKey(p.Key), string.Join(",", p.Value))));
+				var badKeysFormatted = string.Join(", ", dupKeys.Select(p => $"{logKey(p.Key)}: [{string.Join(",", p.Value)}]"));
-				var msg = "{0}, duplicate values found for the following keys: {1}".F(debugName, badKeysFormatted);
+				var msg = $"{debugName}, duplicate values found for the following keys: {badKeysFormatted}";
 				throw new ArgumentException(msg);
 			}
 

OpenRA.Game/FieldLoader.cs

@@ -58,12 +58,12 @@ namespace OpenRA
 
 		public static Func<string, Type, string, object> InvalidValueAction = (s, t, f) =>
 		{
-			throw new YamlException("FieldLoader: Cannot parse `{0}` into `{1}.{2}` ".F(s, f, t));
+			throw new YamlException($"FieldLoader: Cannot parse `{s}` into `{f}.{t}` ");
 		};
 
 		public static Action<string, Type> UnknownFieldAction = (s, f) =>
 		{
-			throw new NotImplementedException("FieldLoader: Missing field `{0}` on `{1}`".F(s, f.Name));
+			throw new NotImplementedException($"FieldLoader: Missing field `{s}` on `{f.Name}`");
 		};
 
 		static readonly ConcurrentCache<Type, FieldLoadInfo[]> TypeLoadInfo =
@@ -660,7 +660,7 @@ namespace OpenRA
 				}
 			}
 
-			UnknownFieldAction("[Type] {0}".F(value), fieldType);
+			UnknownFieldAction($"[Type] {value}", fieldType);
 			return null;
 		}
 
@@ -771,7 +771,7 @@ namespace OpenRA
 				{
 					var method = type.GetMethod(Loader, Flags);
 					if (method == null)
-						throw new InvalidOperationException("{0} does not specify a loader function '{1}'".F(type.Name, Loader));
+						throw new InvalidOperationException($"{type.Name} does not specify a loader function '{Loader}'");
 
 					return (Func<MiniYaml, object>)Delegate.CreateDelegate(typeof(Func<MiniYaml, object>), method);
 				}

OpenRA.Game/FieldSaver.cs

@@ -94,7 +94,7 @@ namespace OpenRA
 					var formattedKey = FormatValue(key);
 					var formattedValue = FormatValue(value);
 
-					result += "{0}: {1}{2}".F(formattedKey, formattedValue, Environment.NewLine);
+					result += $"{formattedKey}: {formattedValue}{Environment.NewLine}";
 				}
 
 				return result;

OpenRA.Game/FileFormats/Png.cs

@@ -213,7 +213,7 @@ namespace OpenRA.FileFormats
 				}
 
 				default:
-					throw new InvalidDataException("Unhandled SpriteFrameType {0}".F(type));
+					throw new InvalidDataException($"Unhandled SpriteFrameType {type}");
 			}
 
 			if (embeddedData != null)

OpenRA.Game/FileFormats/ReplayMetadata.cs

@@ -44,7 +44,7 @@ namespace OpenRA.FileFormats
 			// Read version
 			var version = fs.ReadInt32();
 			if (version != MetaVersion)
-				throw new NotSupportedException("Metadata version {0} is not supported".F(version));
+				throw new NotSupportedException($"Metadata version {version} is not supported");
 
 			// Read game info (max 100K limit as a safeguard against corrupted files)
 			var data = fs.ReadString(Encoding.UTF8, 1024 * 100);

OpenRA.Game/FileSystem/FileSystem.cs

@@ -95,7 +95,7 @@ namespace OpenRA.FileSystem
 					name = name.Substring(1);
 
 					if (!installedMods.TryGetValue(name, out var mod))
-						throw new InvalidOperationException("Could not load mod '{0}'. Available mods: {1}".F(name, installedMods.Keys.JoinWith(", ")));
+						throw new InvalidOperationException($"Could not load mod '{name}'. Available mods: {installedMods.Keys.JoinWith(", ")}");
 
 					package = mod.Package;
 					modPackages.Add(package);
@@ -104,7 +104,7 @@ namespace OpenRA.FileSystem
 				{
 					package = OpenPackage(name);
 					if (package == null)
-						throw new InvalidOperationException("Could not open package '{0}', file not found or its format is not supported.".F(name));
+						throw new InvalidOperationException($"Could not open package '{name}', file not found or its format is not supported.");
 				}
 
 				Mount(package, explicitName);
@@ -203,7 +203,7 @@ namespace OpenRA.FileSystem
 		public Stream Open(string filename)
 		{
 			if (!TryOpen(filename, out var s))
-				throw new FileNotFoundException("File not found: {0}".F(filename), filename);
+				throw new FileNotFoundException($"File not found: {filename}", filename);
 
 			return s;
 		}

OpenRA.Game/Game.cs

@@ -216,7 +216,7 @@ namespace OpenRA
 
 			var orders = new[]
 			{
-					Order.Command("sync_lobby {0}".F(lobbyInfo.Serialize())),
+					Order.Command($"sync_lobby {lobbyInfo.Serialize()}"),
 					Order.Command("startgame")
 			};
 
@@ -439,7 +439,7 @@ namespace OpenRA
 				throw new InvalidOperationException("Game.Mod argument missing.");
 
 			if (!Mods.ContainsKey(mod))
-				throw new InvalidOperationException("Unknown or invalid mod '{0}'.".F(mod));
+				throw new InvalidOperationException($"Unknown or invalid mod '{mod}'.");
 
 			Console.WriteLine("Loading mod: {0}", mod);
 
@@ -988,8 +988,8 @@ namespace OpenRA
 		{
 			var orders = new List<Order>
 			{
-				Order.Command("option gamespeed {0}".F("default")),
+				Order.Command("option gamespeed default"),
-				Order.Command("state {0}".F(Session.ClientState.Ready))
+				Order.Command($"state {Session.ClientState.Ready}")
 			};
 
 			var path = Platform.ResolvePath(launchMap);
@@ -997,7 +997,7 @@ namespace OpenRA
 				ModData.MapCache.SingleOrDefault(m => m.Package.Name == path);
 
 			if (map == null)
-				throw new InvalidOperationException("Could not find map '{0}'.".F(launchMap));
+				throw new InvalidOperationException($"Could not find map '{launchMap}'.");
 
 			CreateAndStartLocalServer(map.Uid, orders);
 		}

OpenRA.Game/GameInformation.cs

@@ -76,7 +76,7 @@ namespace OpenRA
 			}
 			catch (YamlException)
 			{
-				Log.Write("debug", "GameInformation deserialized invalid MiniYaml:\n{0}".F(data));
+				Log.Write("debug", $"GameInformation deserialized invalid MiniYaml:\n{data}");
 				throw;
 			}
 		}
@@ -89,7 +89,7 @@ namespace OpenRA
 			};
 
 			for (var i = 0; i < Players.Count; i++)
-				nodes.Add(new MiniYamlNode("Player@{0}".F(i), FieldSaver.Save(Players[i])));
+				nodes.Add(new MiniYamlNode($"Player@{i}", FieldSaver.Save(Players[i])));
 
 			return nodes.WriteToString();
 		}

OpenRA.Game/GameRules/ActorInfo.cs

@@ -61,7 +61,7 @@ namespace OpenRA
 			}
 			catch (YamlException e)
 			{
-				throw new YamlException("Actor type {0}: {1}".F(name, e.Message));
+				throw new YamlException($"Actor type {name}: {e.Message}");
 			}
 		}
 
@@ -76,8 +76,7 @@ namespace OpenRA
 		static TraitInfo LoadTraitInfo(ObjectCreator creator, string traitName, MiniYaml my)
 		{
 			if (!string.IsNullOrEmpty(my.Value))
-				throw new YamlException("Junk value `{0}` on trait node {1}"
+				throw new YamlException($"Junk value `{my.Value}` on trait node {traitName}");
-				.F(my.Value, traitName));
 
 			// HACK: The linter does not want to crash when a trait doesn't exist but only print an error instead
 			// ObjectCreator will only return null to signal us to abort here if the linter is running

OpenRA.Game/GameRules/Ruleset.cs

@@ -60,7 +60,7 @@ namespace OpenRA
 					}
 					catch (YamlException e)
 					{
-						throw new YamlException("Actor type {0}: {1}".F(a.Name, e.Message));
+						throw new YamlException($"Actor type {a.Name}: {e.Message}");
 					}
 				}
 			}
@@ -75,7 +75,7 @@ namespace OpenRA
 					}
 					catch (YamlException e)
 					{
-						throw new YamlException("Projectile type {0}: {1}".F(weapon.Key, e.Message));
+						throw new YamlException($"Projectile type {weapon.Key}: {e.Message}");
 					}
 				}
 
@@ -89,7 +89,7 @@ namespace OpenRA
 						}
 						catch (YamlException e)
 						{
-							throw new YamlException("Weapon type {0}: {1}".F(weapon.Key, e.Message));
+							throw new YamlException($"Weapon type {weapon.Key}: {e.Message}");
 						}
 					}
 				}

OpenRA.Game/GameSpeed.cs

@@ -50,7 +50,7 @@ namespace OpenRA
 				catch (FieldLoader.MissingFieldsException e)
 				{
 					var label = e.Missing.Length > 1 ? "Required properties missing" : "Required property missing";
-					throw new YamlException("Error parsing GameSpeed {0}: {1}: {2}".F(node.Key, label, e.Missing.JoinWith(", ")));
+					throw new YamlException($"Error parsing GameSpeed {node.Key}: {label}: {e.Missing.JoinWith(", ")}");
 				}
 			}
 

OpenRA.Game/Graphics/CursorManager.cs

@@ -231,7 +231,7 @@ namespace OpenRA.Graphics
 
 			// All palettes must be explicitly referenced, even if they are embedded in the sprite.
 			if (palette == null)
-				throw new InvalidOperationException("Cursor sequence `{0}` attempted to load an indexed sprite but does not define Palette".F(name));
+				throw new InvalidOperationException($"Cursor sequence `{name}` attempted to load an indexed sprite but does not define Palette");
 
 			var width = frame.Size.Width;
 			var height = frame.Size.Height;

OpenRA.Game/Graphics/CursorProvider.cs

@@ -59,7 +59,7 @@ namespace OpenRA.Graphics
 			try { return Cursors[cursor]; }
 			catch (KeyNotFoundException)
 			{
-				throw new InvalidOperationException("Cursor does not have a sequence `{0}`".F(cursor));
+				throw new InvalidOperationException($"Cursor does not have a sequence `{cursor}`");
 			}
 		}
 	}

OpenRA.Game/Graphics/HardwarePalette.cs

@@ -40,20 +40,20 @@ namespace OpenRA.Graphics
 				return mutable.AsReadOnly();
 			if (palettes.TryGetValue(name, out var immutable))
 				return immutable;
-			throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+			throw new InvalidOperationException($"Palette `{name}` does not exist");
 		}
 
 		public int GetPaletteIndex(string name)
 		{
 			if (!indices.TryGetValue(name, out var ret))
-				throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+				throw new InvalidOperationException($"Palette `{name}` does not exist");
 			return ret;
 		}
 
 		public void AddPalette(string name, ImmutablePalette p, bool allowModifiers)
 		{
 			if (palettes.ContainsKey(name))
-				throw new InvalidOperationException("Palette {0} has already been defined".F(name));
+				throw new InvalidOperationException($"Palette {name} has already been defined");
 
 			int index = palettes.Count;
 			indices.Add(name, index);
@@ -78,7 +78,7 @@ namespace OpenRA.Graphics
 			else if (palettes.ContainsKey(name))
 				CopyPaletteToBuffer(indices[name], palettes[name] = new ImmutablePalette(p));
 			else
-				throw new InvalidOperationException("Palette `{0}` does not exist".F(name));
+				throw new InvalidOperationException($"Palette `{name}` does not exist");
 			CopyBufferToTexture();
 		}
 

OpenRA.Game/Graphics/ModelRenderer.cs

@@ -205,7 +205,7 @@ namespace OpenRA.Graphics
 						var t = m.Model.TransformationMatrix(i, frame);
 						var it = Util.MatrixInverse(t);
 						if (it == null)
-							throw new InvalidOperationException("Failed to invert the transformed matrix of frame {0} during RenderAsync.".F(i));
+							throw new InvalidOperationException($"Failed to invert the transformed matrix of frame {i} during RenderAsync.");
 
 						// Transform light vector from shadow -> world -> limb coords
 						var lightDirection = ExtractRotationVector(Util.MatrixMultiply(it, lightTransform));

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -72,10 +72,10 @@ namespace OpenRA.Graphics
 		public ISpriteSequence GetSequence(string unitName, string sequenceName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			if (!unitSeq.Value.TryGetValue(sequenceName, out var seq))
-				throw new InvalidOperationException("Unit `{0}` does not have a sequence named `{1}`".F(unitName, sequenceName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have a sequence named `{sequenceName}`");
 
 			return seq;
 		}
@@ -90,7 +90,7 @@ namespace OpenRA.Graphics
 		public bool HasSequence(string unitName, string sequenceName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			return unitSeq.Value.ContainsKey(sequenceName);
 		}
@@ -98,7 +98,7 @@ namespace OpenRA.Graphics
 		public IEnumerable<string> Sequences(string unitName)
 		{
 			if (!sequences.Value.TryGetValue(unitName, out var unitSeq))
-				throw new InvalidOperationException("Unit `{0}` does not have any sequences defined.".F(unitName));
+				throw new InvalidOperationException($"Unit `{unitName}` does not have any sequences defined.");
 
 			return unitSeq.Value.Keys;
 		}

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -61,7 +61,7 @@ namespace OpenRA.Graphics
 				case SpriteFrameType.Rgba32:
 				case SpriteFrameType.Rgb24:
 					return SheetType.BGRA;
-				default: throw new NotImplementedException("Unknown SpriteFrameType {0}".F(t));
+				default: throw new NotImplementedException($"Unknown SpriteFrameType {t}");
 			}
 		}
 

OpenRA.Game/Graphics/SpriteFont.cs

@@ -43,7 +43,7 @@ namespace OpenRA.Graphics
 
 			// Pre-cache small font sizes so glyphs are immediately available when we need them
 			if (size <= 24)
-				using (new PerfTimer("Precache {0} {1}px".F(name, size)))
+				using (new PerfTimer($"Precache {name} {size}px"))
 					for (var n = (char)0x20; n < (char)0x7f; n++)
 						if (glyphs[n] == null)
 							throw new InvalidOperationException();

OpenRA.Game/Graphics/SpriteRenderer.cs

@@ -19,7 +19,7 @@ namespace OpenRA.Graphics
 	public class SpriteRenderer : Renderer.IBatchRenderer
 	{
 		public const int SheetCount = 7;
-		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => "Texture{0}".F(i));
+		static readonly string[] SheetIndexToTextureName = Exts.MakeArray(SheetCount, i => $"Texture{i}");
 
 		readonly Renderer renderer;
 		readonly IShader shader;
@@ -173,7 +173,7 @@ namespace OpenRA.Graphics
 		// PERF: methods that throw won't be inlined by the JIT, so extract a static helper for use on hot paths
 		static void ThrowSheetOverflow(string paramName)
 		{
-			throw new ArgumentException("SpriteRenderer only supports {0} simultaneous textures".F(SheetCount), paramName);
+			throw new ArgumentException($"SpriteRenderer only supports {SheetCount} simultaneous textures", paramName);
 		}
 
 		// For RGBAColorRenderer

OpenRA.Game/Graphics/Util.cs

@@ -108,7 +108,7 @@ namespace OpenRA.Graphics
 									}
 
 									default:
-										throw new InvalidOperationException("Unknown SpriteFrameType {0}".F(srcType));
+										throw new InvalidOperationException($"Unknown SpriteFrameType {srcType}");
 								}
 
 								var cc = Color.FromArgb(a, r, g, b);
@@ -181,7 +181,7 @@ namespace OpenRA.Graphics
 
 								// Pngs don't support BGR[A], so no need to include them here
 								default:
-									throw new InvalidOperationException("Unknown SpriteFrameType {0}".F(src.Type));
+									throw new InvalidOperationException($"Unknown SpriteFrameType {src.Type}");
 							}
 
 							data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();

OpenRA.Game/Input/Hotkey.cs

@@ -84,7 +84,7 @@ namespace OpenRA
 			return obj is Hotkey o && (Hotkey?)o == this;
 		}
 
-		public override string ToString() { return "{0} {1}".F(Key, Modifiers.ToString("F")); }
+		public override string ToString() { return $"{Key} {Modifiers.ToString("F")}"; }
 
 		public string DisplayString()
 		{

OpenRA.Game/InstalledMods.cs

@@ -74,7 +74,7 @@ namespace OpenRA
 			}
 			catch (Exception e)
 			{
-				Log.Write("debug", "Load mod '{0}': {1}".F(path, e));
+				Log.Write("debug", $"Load mod '{path}': {e}");
 			}
 
 			package?.Dispose();

OpenRA.Game/Manifest.cs

@@ -113,7 +113,7 @@ namespace OpenRA
 				var filename = nodes[i].Value.Value;
 				var contents = package.GetStream(filename);
 				if (contents == null)
-					throw new YamlException("{0}: File `{1}` not found.".F(nodes[i].Location, filename));
+					throw new YamlException($"{nodes[i].Location}: File `{filename}` not found.");
 
 				nodes.RemoveAt(i);
 				nodes.InsertRange(i, MiniYaml.FromStream(contents, filename));
@@ -182,7 +182,7 @@ namespace OpenRA
 
 				var t = oc.FindType(kv.Key);
 				if (t == null || !typeof(IGlobalModData).IsAssignableFrom(t))
-					throw new InvalidDataException("`{0}` is not a valid mod manifest entry.".F(kv.Key));
+					throw new InvalidDataException($"`{kv.Key}` is not a valid mod manifest entry.");
 
 				IGlobalModData module;
 				var ctor = t.GetConstructor(new[] { typeof(MiniYaml) });

OpenRA.Game/Map/ActorInitializer.cs

@@ -66,7 +66,7 @@ namespace OpenRA
 		{
 			var init = GetOrDefault<T>(info);
 			if (init == null)
-			    throw new InvalidOperationException("TypeDictionary does not contain instance of type `{0}`".F(typeof(T)));
+			    throw new InvalidOperationException($"TypeDictionary does not contain instance of type `{typeof(T)}`");
 
 			return init;
 		}

OpenRA.Game/Map/ActorReference.cs

@@ -42,7 +42,7 @@ namespace OpenRA
 				{
 					var init = LoadInit(i.Key, i.Value);
 					if (init is ISingleInstanceInit && dict.Contains(init.GetType()))
-						throw new InvalidDataException("Duplicate initializer '{0}'".F(init.GetType().Name));
+						throw new InvalidDataException($"Duplicate initializer '{init.GetType().Name}'");
 
 					dict.Add(init);
 				}
@@ -68,7 +68,7 @@ namespace OpenRA
 			var initInstance = initName.Split(ActorInfo.TraitInstanceSeparator);
 			var type = Game.ModData.ObjectCreator.FindType(initInstance[0] + "Init");
 			if (type == null)
-				throw new InvalidDataException("Unknown initializer type '{0}Init'".F(initInstance[0]));
+				throw new InvalidDataException($"Unknown initializer type '{initInstance[0]}Init'");
 
 			var init = (ActorInit)FormatterServices.GetUninitializedObject(type);
 			if (initInstance.Length > 1)
@@ -76,7 +76,7 @@ namespace OpenRA
 
 			var loader = type.GetMethod("Initialize", new[] { typeof(MiniYaml) });
 			if (loader == null)
-				throw new InvalidDataException("{0}Init does not define a yaml-assignable type.".F(initInstance[0]));
+				throw new InvalidDataException($"{initInstance[0]}Init does not define a yaml-assignable type.");
 
 			loader.Invoke(init, new[] { initYaml });
 			return init;
@@ -119,7 +119,7 @@ namespace OpenRA
 		public void Add(ActorInit init)
 		{
 			if (init is ISingleInstanceInit && InitDict.Contains(init.GetType()))
-				throw new InvalidDataException("Duplicate initializer '{0}'".F(init.GetType().Name));
+				throw new InvalidDataException($"Duplicate initializer '{init.GetType().Name}'");
 
 			InitDict.Add(init);
 		}
@@ -162,7 +162,7 @@ namespace OpenRA
 		{
 			var init = GetOrDefault<T>(info);
 			if (init == null)
-				throw new InvalidOperationException("TypeDictionary does not contain instance of type `{0}`".F(typeof(T)));
+				throw new InvalidOperationException($"TypeDictionary does not contain instance of type `{typeof(T)}`");
 
 			return init;
 		}

OpenRA.Game/Map/Map.cs

@@ -53,7 +53,7 @@ namespace OpenRA
 				ResourcesOffset = s.ReadUInt32();
 			}
 			else
-				throw new InvalidDataException("Unknown binary map format '{0}'".F(Format));
+				throw new InvalidDataException($"Unknown binary map format '{Format}'");
 		}
 	}
 
@@ -100,7 +100,7 @@ namespace OpenRA
 			if (node == null)
 			{
 				if (required)
-					throw new YamlException("Required field `{0}` not found in map.yaml".F(key));
+					throw new YamlException($"Required field `{key}` not found in map.yaml");
 				return;
 			}
 
@@ -258,7 +258,7 @@ namespace OpenRA
 			var contents = package.Contents.ToList();
 			foreach (var required in requiredFiles)
 				if (!contents.Contains(required))
-					throw new FileNotFoundException("Required file {0} not present in this map".F(required));
+					throw new FileNotFoundException($"Required file {required} not present in this map");
 
 			var streams = new List<Stream>();
 			try
@@ -326,18 +326,18 @@ namespace OpenRA
 			Package = package;
 
 			if (!Package.Contains("map.yaml") || !Package.Contains("map.bin"))
-				throw new InvalidDataException("Not a valid map\n File: {0}".F(package.Name));
+				throw new InvalidDataException($"Not a valid map\n File: {package.Name}");
 
 			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), package.Name));
 			foreach (var field in YamlFields)
 				field.Deserialize(this, yaml.Nodes);
 
 			if (MapFormat != SupportedMapFormat)
-				throw new InvalidDataException("Map format {0} is not supported.\n File: {1}".F(MapFormat, package.Name));
+				throw new InvalidDataException($"Map format {MapFormat} is not supported.\n File: {package.Name}");
 
 			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
 			if (PlayerDefinitions.Count > 64)
-				throw new InvalidDataException("Maps must not define more than 64 players.\n File: {0}".F(package.Name));
+				throw new InvalidDataException($"Maps must not define more than 64 players.\n File: {package.Name}");
 
 			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");
 
@@ -1251,7 +1251,7 @@ namespace OpenRA
 
 			if (maxRange >= Grid.TilesByDistance.Length)
 				throw new ArgumentOutOfRangeException(nameof(maxRange),
-					"The requested range ({0}) cannot exceed the value of MaximumTileSearchRange ({1})".F(maxRange, Grid.MaximumTileSearchRange));
+					$"The requested range ({maxRange}) cannot exceed the value of MaximumTileSearchRange ({Grid.MaximumTileSearchRange})");
 
 			for (var i = minRange; i <= maxRange; i++)
 			{

OpenRA.Game/Map/MapPlayers.cs

@@ -50,7 +50,7 @@ namespace OpenRA
 						Name = "Creeps",
 						Faction = firstFaction,
 						NonCombatant = true,
-						Enemies = Exts.MakeArray(playerCount, i => "Multi{0}".F(i))
+						Enemies = Exts.MakeArray(playerCount, i => $"Multi{i}")
 					}
 				}
 			};
@@ -59,7 +59,7 @@ namespace OpenRA
 			{
 				var p = new PlayerReference
 				{
-					Name = "Multi{0}".F(index),
+					Name = $"Multi{index}",
 					Faction = "Random",
 					Playable = true,
 					Enemies = new[] { "Creeps" }
@@ -70,7 +70,7 @@ namespace OpenRA
 
 		public List<MiniYamlNode> ToMiniYaml()
 		{
-			return Players.Select(p => new MiniYamlNode("PlayerReference@{0}".F(p.Key),
+			return Players.Select(p => new MiniYamlNode($"PlayerReference@{p.Key}",
 				FieldSaver.SaveDifferences(p.Value, new PlayerReference()))).ToList();
 		}
 	}

OpenRA.Game/Map/MapPreview.cs

@@ -324,7 +324,7 @@ namespace OpenRA
 			{
 				var format = FieldLoader.GetValue<int>("MapFormat", temp.Value);
 				if (format != Map.SupportedMapFormat)
-					throw new InvalidDataException("Map format {0} is not supported.".F(format));
+					throw new InvalidDataException($"Map format {format} is not supported.");
 			}
 
 			if (yaml.TryGetValue("Title", out temp))

OpenRA.Game/MiniYaml.cs

@@ -45,7 +45,7 @@ namespace OpenRA
 		public struct SourceLocation
 		{
 			public string Filename; public int Line;
-			public override string ToString() { return "{0}:{1}".F(Filename, Line); }
+			public override string ToString() { return $"{Filename}:{Line}"; }
 		}
 
 		public SourceLocation Location;
@@ -80,7 +80,7 @@ namespace OpenRA
 
 		public override string ToString()
 		{
-			return "{{YamlNode: {0} @ {1}}}".F(Key, Location);
+			return $"{{YamlNode: {Key} @ {Location}}}";
 		}
 
 		public MiniYamlNode Clone()
@@ -129,7 +129,7 @@ namespace OpenRA
 				}
 				catch (ArgumentException ex)
 				{
-					throw new InvalidDataException("Duplicate key '{0}' in {1}".F(y.Key, y.Location), ex);
+					throw new InvalidDataException($"Duplicate key '{y.Key}' in {y.Location}", ex);
 				}
 			}
 
@@ -205,7 +205,7 @@ namespace OpenRA
 					}
 
 					if (levels.Count <= level)
-						throw new YamlException("Bad indent in miniyaml at {0}".F(location));
+						throw new YamlException($"Bad indent in miniyaml at {location}");
 
 					while (levels.Count > level + 1)
 						levels.RemoveAt(levels.Count - 1);
@@ -361,11 +361,10 @@ namespace OpenRA
 				{
 					if (!tree.TryGetValue(n.Value.Value, out var parent))
 						throw new YamlException(
-							"{0}: Parent type `{1}` not found".F(n.Location, n.Value.Value));
+							$"{n.Location}: Parent type `{n.Value.Value}` not found");
 
 					if (inherited.ContainsKey(n.Value.Value))
-						throw new YamlException("{0}: Parent type `{1}` was already inherited by this yaml tree at {2} (note: may be from a derived tree)"
+						throw new YamlException($"{n.Location}: Parent type `{n.Value.Value}` was already inherited by this yaml tree at {inherited[n.Value.Value]} (note: may be from a derived tree)");
-							.F(n.Location, n.Value.Value, inherited[n.Value.Value]));
 
 					inherited.Add(n.Value.Value, n.Location);
 					foreach (var r in ResolveInherits(n.Key, parent, tree, inherited))
@@ -375,7 +374,7 @@ namespace OpenRA
 				{
 					var removed = n.Key.Substring(1);
 					if (resolved.RemoveAll(r => r.Key == removed) == 0)
-						throw new YamlException("{0}: There are no elements with key `{1}` to remove".F(n.Location, removed));
+						throw new YamlException($"{n.Location}: There are no elements with key `{removed}` to remove");
 				}
 				else
 					MergeIntoResolved(n, resolved, tree, inherited);
@@ -443,8 +442,8 @@ namespace OpenRA
 
 			var ret = new List<MiniYamlNode>();
 
-			var existingDict = existingNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => "{0} (at {1})".F(x.Key, x.Location));
+			var existingDict = existingNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
-			var overrideDict = overrideNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => "{0} (at {1})".F(x.Key, x.Location));
+			var overrideDict = overrideNodes.ToDictionaryWithConflictLog(x => x.Key, "MiniYaml.Merge", null, x => $"{x.Key} (at {x.Location})");
 			var allKeys = existingDict.Keys.Union(overrideDict.Keys);
 
 			foreach (var key in allKeys)

OpenRA.Game/ModData.cs

@@ -81,7 +81,7 @@ namespace OpenRA
 			var terrainLoader = ObjectCreator.FindType(terrainFormat.Type + "Loader");
 			var terrainCtor = terrainLoader?.GetConstructor(new[] { typeof(ModData) });
 			if (terrainLoader == null || !terrainLoader.GetInterfaces().Contains(typeof(ITerrainLoader)) || terrainCtor == null)
-				throw new InvalidOperationException("Unable to find a terrain loader for type '{0}'.".F(terrainFormat.Type));
+				throw new InvalidOperationException($"Unable to find a terrain loader for type '{terrainFormat.Type}'.");
 
 			TerrainLoader = (ITerrainLoader)terrainCtor.Invoke(new[] { this });
 
@@ -89,7 +89,7 @@ namespace OpenRA
 			var sequenceLoader = ObjectCreator.FindType(sequenceFormat.Type + "Loader");
 			var sequenceCtor = sequenceLoader != null ? sequenceLoader.GetConstructor(new[] { typeof(ModData) }) : null;
 			if (sequenceLoader == null || !sequenceLoader.GetInterfaces().Contains(typeof(ISpriteSequenceLoader)) || sequenceCtor == null)
-				throw new InvalidOperationException("Unable to find a sequence loader for type '{0}'.".F(sequenceFormat.Type));
+				throw new InvalidOperationException($"Unable to find a sequence loader for type '{sequenceFormat.Type}'.");
 
 			SpriteSequenceLoader = (ISpriteSequenceLoader)sequenceCtor.Invoke(new[] { this });
 
@@ -97,7 +97,7 @@ namespace OpenRA
 			var modelLoader = ObjectCreator.FindType(modelFormat.Type + "Loader");
 			var modelCtor = modelLoader != null ? modelLoader.GetConstructor(new[] { typeof(ModData) }) : null;
 			if (modelLoader == null || !modelLoader.GetInterfaces().Contains(typeof(IModelSequenceLoader)) || modelCtor == null)
-				throw new InvalidOperationException("Unable to find a model loader for type '{0}'.".F(modelFormat.Type));
+				throw new InvalidOperationException($"Unable to find a model loader for type '{modelFormat.Type}'.");
 
 			ModelSequenceLoader = (IModelSequenceLoader)modelCtor.Invoke(new[] { this });
 			ModelSequenceLoader.OnMissingModelError = s => Log.Write("debug", s);
@@ -156,7 +156,7 @@ namespace OpenRA
 			LoadScreen?.Display();
 
 			if (MapCache[uid].Status != MapStatus.Available)
-				throw new InvalidDataException("Invalid map uid: {0}".F(uid));
+				throw new InvalidDataException($"Invalid map uid: {uid}");
 
 			Map map;
 			using (new Support.PerfTimer("Map"))

OpenRA.Game/Network/Connection.cs

@@ -156,7 +156,7 @@ namespace OpenRA.Network
 			this.target = target;
 			new Thread(NetworkConnectionConnect)
 			{
-				Name = "{0} (connect to {1})".F(GetType().Name, target),
+				Name = $"{GetType().Name} (connect to {target})",
 				IsBackground = true
 			}.Start();
 		}
@@ -189,11 +189,11 @@ namespace OpenRA.Network
 					catch (Exception ex)
 					{
 						errorMessage = "Failed to connect";
-						Log.Write("client", "Failed to connect to {0}: {1}".F(endpoint, ex.Message));
+						Log.Write("client", $"Failed to connect to {endpoint}: {ex.Message}");
 					}
 				})
 				{
-					Name = "{0} (connect to {1})".F(GetType().Name, endpoint),
+					Name = $"{GetType().Name} (connect to {endpoint})",
 					IsBackground = true
 				}.Start();
 			}
@@ -212,7 +212,7 @@ namespace OpenRA.Network
 
 				new Thread(NetworkConnectionReceive)
 				{
-					Name = "{0} (receive from {1})".F(GetType().Name, tcp.Client.RemoteEndPoint),
+					Name = $"{GetType().Name} (receive from {tcp.Client.RemoteEndPoint})",
 					IsBackground = true
 				}.Start();
 			}
@@ -235,9 +235,7 @@ namespace OpenRA.Network
 				var handshakeProtocol = reader.ReadInt32();
 
 				if (handshakeProtocol != ProtocolVersion.Handshake)
-					throw new InvalidOperationException(
+					throw new InvalidOperationException($"Handshake protocol version mismatch. Server={handshakeProtocol} Client={ProtocolVersion.Handshake}");
-						"Handshake protocol version mismatch. Server={0} Client={1}"
-							.F(handshakeProtocol, ProtocolVersion.Handshake));
 
 				clientId = reader.ReadInt32();
 				connectionState = ConnectionState.Connected;
@@ -255,7 +253,7 @@ namespace OpenRA.Network
 			catch (Exception ex)
 			{
 				errorMessage = "Connection failed";
-				Log.Write("client", "Connection to {0} failed: {1}".F(endpoint, ex.Message));
+				Log.Write("client", $"Connection to {endpoint} failed: {ex.Message}");
 			}
 			finally
 			{

OpenRA.Game/Network/ConnectionTarget.cs

@@ -56,7 +56,7 @@ namespace OpenRA.Network
 		public override string ToString()
 		{
 			return endpoints
-				.Select(e => "{0}:{1}".F(e.Host, e.Port))
+				.Select(e => $"{e.Host}:{e.Port}")
 				.JoinWith("/");
 		}
 	}

OpenRA.Game/Network/FrameData.cs

@@ -23,7 +23,7 @@ namespace OpenRA.Network
 
 			public override string ToString()
 			{
-				return "ClientId: {0} {1}".F(Client, Order);
+				return $"ClientId: {Client} {Order}";
 			}
 		}
 

OpenRA.Game/Network/GameSave.cs

@@ -71,7 +71,7 @@ namespace OpenRA.Network
 
 		public MiniYamlNode Serialize(string key)
 		{
-			return new MiniYamlNode("SlotClient@{0}".F(key), FieldSaver.Save(this));
+			return new MiniYamlNode($"SlotClient@{key}", FieldSaver.Save(this));
 		}
 	}
 
@@ -195,7 +195,7 @@ namespace OpenRA.Network
 			{
 				if (data.Length != Order.SyncHashOrderLength)
 				{
-					Log.Write("debug", "Dropped sync order with length {0}. Expected length {1}.".F(data.Length, Order.SyncHashOrderLength));
+					Log.Write("debug", $"Dropped sync order with length {data.Length}. Expected length {Order.SyncHashOrderLength}.");
 					return;
 				}
 

OpenRA.Game/Network/GameServer.cs

@@ -135,7 +135,7 @@ namespace OpenRA.Network
 		/// <summary>The list of spawnpoints that are disabled for this game</summary>
 		public readonly int[] DisabledSpawnPoints = { };
 
-		public string ModLabel => "{0} ({1})".F(ModTitle, Version);
+		public string ModLabel => $"{ModTitle} ({Version})";
 
 		static object LoadClients(MiniYaml yaml)
 		{
@@ -200,9 +200,9 @@ namespace OpenRA.Network
 						.FirstOrDefault(m => m.Id == Mod);
 
 					if (guessMod != null)
-						ModTitle = "{0}".F(guessMod.Title);
+						ModTitle = guessMod.Title;
 					else
-						ModTitle = "Unknown mod: {0}".F(Mod);
+						ModTitle = $"Unknown mod: {Mod}";
 				}
 			}
 

OpenRA.Game/Network/Order.cs

@@ -405,7 +405,7 @@ namespace OpenRA
 				}
 
 				default:
-					throw new InvalidDataException("Cannot serialize order type {0}".F(Type));
+					throw new InvalidDataException($"Cannot serialize order type {Type}");
 			}
 
 			return ret.ToArray();
@@ -413,10 +413,8 @@ namespace OpenRA
 
 		public override string ToString()
 		{
-			return ("OrderString: \"{0}\" \n\t Type: \"{1}\".  \n\t Subject: \"{2}\". \n\t Target: \"{3}\"." +
+			return $"OrderString: \"{OrderString}\" \n\t Type: \"{Type}\".  \n\t Subject: \"{Subject}\". \n\t Target: \"{Target}\"." +
-				"\n\t TargetString: \"{4}\".\n\t IsImmediate: {5}.\n\t Player(PlayerName): {6}\n").F(
+					$"\n\t TargetString: \"{TargetString}\".\n\t IsImmediate: {IsImmediate}.\n\t Player(PlayerName): {Player?.PlayerName}\n";
-				OrderString, Type, Subject, Target, TargetString, IsImmediate,
-				Player != null ? Player.PlayerName : null);
 		}
 	}
 }

OpenRA.Game/Network/OrderManager.cs

@@ -60,7 +60,7 @@ namespace OpenRA.Network
 		void OutOfSync(int frame)
 		{
 			syncReport.DumpSyncReport(frame, frameData.OrdersForFrame(World, frame));
-			throw new InvalidOperationException("Out of sync in frame {0}.\n Compare syncreport.log with other players.".F(frame));
+			throw new InvalidOperationException($"Out of sync in frame {frame}.\n Compare syncreport.log with other players.");
 		}
 
 		public void StartGame()
@@ -126,7 +126,7 @@ namespace OpenRA.Network
 					{
 						if (packet.Length != 4 + Order.SyncHashOrderLength)
 						{
-							Log.Write("debug", "Dropped sync order with length {0}. Expected length {1}.".F(packet.Length, 4 + Order.SyncHashOrderLength));
+							Log.Write("debug", $"Dropped sync order with length {packet.Length}. Expected length {4 + Order.SyncHashOrderLength}.");
 							return;
 						}
 

OpenRA.Game/Network/ReplayRecorder.cs

@@ -56,7 +56,7 @@ namespace OpenRA.Network
 			var id = -1;
 			while (file == null)
 			{
-				var fullFilename = Path.Combine(dir, id < 0 ? "{0}.orarep".F(filename) : "{0}-{1}.orarep".F(filename, id));
+				var fullFilename = Path.Combine(dir, id < 0 ? $"{filename}.orarep" : $"{filename}-{id}.orarep");
 				id++;
 				try
 				{
@@ -65,8 +65,7 @@ namespace OpenRA.Network
 				catch (IOException ex)
 				{
 					if (id > CreateReplayFileMaxRetryCount)
-						throw new ArgumentException(
+						throw new ArgumentException($"Error creating replay file \"{filename}.orarep\"", ex);
-							"Error creating replay file \"{0}.orarep\"".F(filename), ex);
 				}
 			}
 

OpenRA.Game/Network/Session.cs

@@ -37,7 +37,7 @@ namespace OpenRA.Network
 			{
 				// Follow convention used by Google Analytics: remove last octet
 				var b = ip.GetAddressBytes();
-				return "{0}.{1}.{2}.*".F(b[0], b[1], b[2]);
+				return $"{b[0]}.{b[1]}.{b[2]}.*";
 			}
 
 			return null;
@@ -82,11 +82,11 @@ namespace OpenRA.Network
 			}
 			catch (YamlException)
 			{
-				throw new YamlException("Session deserialized invalid MiniYaml:\n{0}".F(data));
+				throw new YamlException($"Session deserialized invalid MiniYaml:\n{data}");
 			}
 			catch (InvalidOperationException)
 			{
-				throw new YamlException("Session deserialized invalid MiniYaml:\n{0}".F(data));
+				throw new YamlException($"Session deserialized invalid MiniYaml:\n{data}");
 			}
 		}
 
@@ -159,7 +159,7 @@ namespace OpenRA.Network
 
 			public MiniYamlNode Serialize()
 			{
-				return new MiniYamlNode("Client@{0}".F(Index), FieldSaver.Save(this));
+				return new MiniYamlNode($"Client@{Index}", FieldSaver.Save(this));
 			}
 		}
 
@@ -182,7 +182,7 @@ namespace OpenRA.Network
 
 			public MiniYamlNode Serialize()
 			{
-				return new MiniYamlNode("ClientPing@{0}".F(Index), FieldSaver.Save(this));
+				return new MiniYamlNode($"ClientPing@{Index}", FieldSaver.Save(this));
 			}
 		}
 
@@ -206,7 +206,7 @@ namespace OpenRA.Network
 
 			public MiniYamlNode Serialize()
 			{
-				return new MiniYamlNode("Slot@{0}".F(PlayerReference), FieldSaver.Save(this));
+				return new MiniYamlNode($"Slot@{PlayerReference}", FieldSaver.Save(this));
 			}
 		}
 

OpenRA.Game/Network/SyncReport.cs

@@ -117,12 +117,12 @@ namespace OpenRA.Network
 					Log.Write("sync", "Synced Traits:");
 					foreach (var a in r.Traits)
 					{
-						Log.Write("sync", "\t {0} {1} {2} {3} ({4})".F(a.ActorID, a.Type, a.Owner, a.Trait, a.Hash));
+						Log.Write("sync", $"\t {a.ActorID} {a.Type} {a.Owner} {a.Trait} ({a.Hash})");
 
 						var nvp = a.NamesValues;
 						for (int i = 0; i < nvp.Names.Length; i++)
 							if (nvp.Values[i] != null)
-								Log.Write("sync", "\t\t {0}: {1}".F(nvp.Names[i], nvp.Values[i]));
+								Log.Write("sync", $"\t\t {nvp.Names[i]}: {nvp.Values[i]}");
 					}
 
 					Log.Write("sync", "Synced Effects:");
@@ -133,7 +133,7 @@ namespace OpenRA.Network
 						var nvp = e.NamesValues;
 						for (int i = 0; i < nvp.Names.Length; i++)
 							if (nvp.Values[i] != null)
-								Log.Write("sync", "\t\t {0}: {1}".F(nvp.Names[i], nvp.Values[i]));
+								Log.Write("sync", $"\t\t {nvp.Names[i]}: {nvp.Values[i]}");
 					}
 
 					Log.Write("sync", "Orders Issued:");

OpenRA.Game/Network/UnitOrders.cs

@@ -170,7 +170,7 @@ namespace OpenRA.Network
 
 							if (orderManager.World.Paused != pause && world != null && world.LobbyInfo.NonBotClients.Count() > 1)
 							{
-								var pausetext = "The game is {0} by {1}".F(pause ? "paused" : "un-paused", client.Name);
+								var pausetext = $"The game is {(pause ? "paused" : "un-paused")} by {client.Name}";
 								Game.AddSystemLine(pausetext);
 							}
 

OpenRA.Game/ObjectCreator.cs

@@ -41,7 +41,7 @@ namespace OpenRA
 			{
 				var resolvedPath = FileSystem.FileSystem.ResolveAssemblyPath(path, manifest, mods);
 				if (resolvedPath == null)
-					throw new FileNotFoundException("Assembly `{0}` not found.".F(path));
+					throw new FileNotFoundException($"Assembly `{path}` not found.");
 
 				LoadAssembly(assemblyList, resolvedPath);
 			}
@@ -111,7 +111,7 @@ namespace OpenRA
 				if (MissingTypeAction != null)
 					MissingTypeAction(className);
 				else
-					throw new InvalidOperationException("Cannot locate type: {0}".F(className));
+					throw new InvalidOperationException($"Cannot locate type: {className}");
 
 				return default(T);
 			}
@@ -151,7 +151,7 @@ namespace OpenRA
 			for (var i = 0; i < p.Length; i++)
 			{
 				var key = p[i].Name;
-				if (!args.ContainsKey(key)) throw new InvalidOperationException("ObjectCreator: key `{0}' not found".F(key));
+				if (!args.ContainsKey(key)) throw new InvalidOperationException($"ObjectCreator: key `{key}' not found");
 				a[i] = args[key];
 			}
 
@@ -177,7 +177,7 @@ namespace OpenRA
 			{
 				var loader = FindType(format + "Loader");
 				if (loader == null || !loader.GetInterfaces().Contains(typeof(TLoader)))
-					throw new InvalidOperationException("Unable to find a {0} loader for type '{1}'.".F(name, format));
+					throw new InvalidOperationException($"Unable to find a {name} loader for type '{format}'.");
 
 				loaders.Add((TLoader)CreateBasic(loader));
 			}

OpenRA.Game/Platform.cs

@@ -64,13 +64,13 @@ namespace OpenRA
 			{
 				var mono = Type.GetType("Mono.Runtime");
 				if (mono == null)
-					return ".NET CLR {0}".F(Environment.Version);
+					return $".NET CLR {Environment.Version}";
 
 				var version = mono.GetMethod("GetDisplayName", BindingFlags.NonPublic | BindingFlags.Static);
 				if (version == null)
-					return "Mono (unknown version) CLR {0}".F(Environment.Version);
+					return $"Mono (unknown version) CLR {Environment.Version}";
 
-				return "Mono {0} CLR {1}".F(version.Invoke(null, null), Environment.Version);
+				return $"Mono {version.Invoke(null, null)} CLR {Environment.Version}";
 			}
 		}
 

OpenRA.Game/Player.cs

@@ -118,7 +118,7 @@ namespace OpenRA
 				selected = selectableFactions.FirstOrDefault(f => f.InternalName == faction);
 
 				if (selected == null)
-					throw new YamlException("Unknown faction: {0}".F(faction));
+					throw new YamlException($"Unknown faction: {faction}");
 			}
 
 			return selected;
@@ -143,7 +143,7 @@ namespace OpenRA
 			{
 				var botInfo = botInfos.First(b => b.Type == client.Bot);
 				var botsOfSameType = clients.Where(c => c.Bot == client.Bot).ToArray();
-				return botsOfSameType.Length == 1 ? botInfo.Name : "{0} {1}".F(botInfo.Name, botsOfSameType.IndexOf(client) + 1);
+				return botsOfSameType.Length == 1 ? botInfo.Name : $"{botInfo.Name} {botsOfSameType.IndexOf(client) + 1}";
 			}
 
 			return client.Name;
@@ -230,7 +230,7 @@ namespace OpenRA
 
 		public override string ToString()
 		{
-			return "{0} ({1})".F(PlayerName, ClientIndex);
+			return $"{PlayerName} ({ClientIndex})";
 		}
 
 		public PlayerRelationship RelationshipWith(Player other)
@@ -305,7 +305,7 @@ namespace OpenRA
 
 		public LuaValue ToString(LuaRuntime runtime)
 		{
-			return "Player ({0})".F(PlayerName);
+			return $"Player ({PlayerName})";
 		}
 
 		#endregion

OpenRA.Game/Primitives/Rectangle.cs

@@ -126,7 +126,7 @@ namespace OpenRA.Primitives
 
 		public override string ToString()
 		{
-			return "{0},{1},{2},{3}".F(X, Y, Width, Height);
+			return $"{X},{Y},{Width},{Height}";
 		}
 	}
 }

OpenRA.Game/Primitives/Size.cs

@@ -66,7 +66,7 @@ namespace OpenRA.Primitives
 
 		public override string ToString()
 		{
-			return string.Format("{{Width={0}, Height={1}}}", Width, Height);
+			return $"{{Width={Width}, Height={Height}}}";
 		}
 	}
 }

OpenRA.Game/Primitives/SpatiallyPartitioned.cs

@@ -33,7 +33,7 @@ namespace OpenRA.Primitives
 		void ValidateBounds(T actor, Rectangle bounds)
 		{
 			if (bounds.Width == 0 || bounds.Height == 0)
-				throw new ArgumentException("Bounds of actor {0} are empty.".F(actor), nameof(bounds));
+				throw new ArgumentException($"Bounds of actor {actor} are empty.", nameof(bounds));
 		}
 
 		public void Add(T item, Rectangle bounds)

OpenRA.Game/Primitives/TypeDictionary.cs

@@ -64,12 +64,12 @@ namespace OpenRA.Primitives
 			if (!data.TryGetValue(t, out var ret))
 			{
 				if (throwsIfMissing)
-					throw new InvalidOperationException("TypeDictionary does not contain instance of type `{0}`".F(t));
+					throw new InvalidOperationException($"TypeDictionary does not contain instance of type `{t}`");
 				return null;
 			}
 
 			if (ret.Count > 1)
-				throw new InvalidOperationException("TypeDictionary contains multiple instances of type `{0}`".F(t));
+				throw new InvalidOperationException($"TypeDictionary contains multiple instances of type `{t}`");
 			return ret[0];
 		}
 

OpenRA.Game/Primitives/float3.cs

@@ -58,7 +58,7 @@ namespace OpenRA
 			return obj is float3 o && (float3?)o == this;
 		}
 
-		public override string ToString() { return "{0},{1},{2}".F(X, Y, Z); }
+		public override string ToString() { return $"{X},{Y},{Z}"; }
 
 		public static readonly float3 Zero = new float3(0, 0, 0);
 		public static readonly float3 Ones = new float3(1, 1, 1);

OpenRA.Game/Renderer.cs

@@ -181,7 +181,7 @@ namespace OpenRA
 		public void BeginWorld(Rectangle worldViewport)
 		{
 			if (renderType != RenderType.None)
-				throw new InvalidOperationException("BeginWorld called with renderType = {0}, expected RenderType.None.".F(renderType));
+				throw new InvalidOperationException($"BeginWorld called with renderType = {renderType}, expected RenderType.None.");
 
 			BeginFrame();
 
@@ -263,7 +263,7 @@ namespace OpenRA
 		public void EndFrame(IInputHandler inputHandler)
 		{
 			if (renderType != RenderType.UI)
-				throw new InvalidOperationException("EndFrame called with renderType = {0}, expected RenderType.UI.".F(renderType));
+				throw new InvalidOperationException($"EndFrame called with renderType = {renderType}, expected RenderType.UI.");
 
 			Flush();
 
@@ -391,7 +391,7 @@ namespace OpenRA
 		public void EnableAntialiasingFilter()
 		{
 			if (renderType != RenderType.UI)
-				throw new InvalidOperationException("EndFrame called with renderType = {0}, expected RenderType.UI.".F(renderType));
+				throw new InvalidOperationException($"EndFrame called with renderType = {renderType}, expected RenderType.UI.");
 
 			Flush();
 			SpriteRenderer.SetAntialiasingPixelsPerTexel(Window.EffectiveWindowScale);
@@ -400,7 +400,7 @@ namespace OpenRA
 		public void DisableAntialiasingFilter()
 		{
 			if (renderType != RenderType.UI)
-				throw new InvalidOperationException("EndFrame called with renderType = {0}, expected RenderType.UI.".F(renderType));
+				throw new InvalidOperationException($"EndFrame called with renderType = {renderType}, expected RenderType.UI.");
 
 			Flush();
 			SpriteRenderer.SetAntialiasingPixelsPerTexel(0);

OpenRA.Game/Scripting/ScriptActorInterface.cs

@@ -18,14 +18,14 @@ namespace OpenRA.Scripting
 	{
 		readonly Actor actor;
 
-		protected override string DuplicateKeyError(string memberName) { return "Actor '{0}' defines the command '{1}' on multiple traits".F(actor.Info.Name, memberName); }
+		protected override string DuplicateKeyError(string memberName) { return $"Actor '{actor.Info.Name}' defines the command '{memberName}' on multiple traits"; }
 		protected override string MemberNotFoundError(string memberName)
 		{
 			var actorName = actor.Info.Name;
 			if (actor.IsDead)
 				actorName += " (dead)";
 
-			return "Actor '{0}' does not define a property '{1}'".F(actorName, memberName);
+			return $"Actor '{actorName}' does not define a property '{memberName}'";
 		}
 
 		public ScriptActorInterface(ScriptContext context, Actor actor)

OpenRA.Game/Scripting/ScriptContext.cs

@@ -81,8 +81,8 @@ namespace OpenRA.Scripting
 	/// </remarks>
 	public abstract class ScriptGlobal : ScriptObjectWrapper
 	{
-		protected override string DuplicateKeyError(string memberName) { return "Table '{0}' defines multiple members '{1}'".F(Name, memberName); }
+		protected override string DuplicateKeyError(string memberName) { return $"Table '{Name}' defines multiple members '{memberName}'"; }
-		protected override string MemberNotFoundError(string memberName) { return "Table '{0}' does not define a property '{1}'".F(Name, memberName); }
+		protected override string MemberNotFoundError(string memberName) { return $"Table '{Name}' does not define a property '{memberName}'"; }
 
 		public readonly string Name;
 		public ScriptGlobal(ScriptContext context)
@@ -92,7 +92,7 @@ namespace OpenRA.Scripting
 			var type = GetType();
 			var names = type.GetCustomAttributes<ScriptGlobalAttribute>(true);
 			if (names.Length != 1)
-				throw new InvalidOperationException("[ScriptGlobal] attribute not found for global table '{0}'".F(type));
+				throw new InvalidOperationException($"[ScriptGlobal] attribute not found for global table '{type}'");
 
 			Name = names.First().Name;
 			Bind(new[] { this });
@@ -187,7 +187,7 @@ namespace OpenRA.Scripting
 					});
 
 					if (ctor == null)
-						throw new InvalidOperationException("{0} must define a constructor that takes a ScriptContext context parameter".F(b.Name));
+						throw new InvalidOperationException($"{b.Name} must define a constructor that takes a ScriptContext context parameter");
 
 					var binding = (ScriptGlobal)ctor.Invoke(new[] { this });
 					using (var obj = binding.ToLuaValue(this))
@@ -236,7 +236,7 @@ namespace OpenRA.Scripting
 			using (var registerGlobal = (LuaFunction)runtime.Globals["RegisterSandboxedGlobal"])
 			{
 				if (runtime.Globals.ContainsKey(name))
-					throw new LuaException("The global name '{0}' is reserved, and may not be used by a map actor".F(name));
+					throw new LuaException($"The global name '{name}' is reserved, and may not be used by a map actor");
 
 				using (var obj = a.ToLuaValue(this))
 					registerGlobal.Call(name, obj).Dispose();

OpenRA.Game/Scripting/ScriptMemberExts.cs

@@ -32,16 +32,16 @@ namespace OpenRA.Scripting
 				ret = t.Name;
 
 			if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>))
-				ret = "{0}?".F(t.GetGenericArguments().Select(p => p.Name).First());
+				ret = $"{t.GetGenericArguments().Select(p => p.Name).First()}?";
 
 			return ret;
 		}
 
 		public static string LuaDocString(this ParameterInfo pi)
 		{
-			var ret = "{0} {1}".F(pi.ParameterType.LuaDocString(), pi.Name);
+			var ret = $"{pi.ParameterType.LuaDocString()} {pi.Name}";
 			if (pi.IsOptional)
-				ret += " = {0}".F(pi.DefaultValue != null ? pi.DefaultValue : "nil");
+				ret += $" = {pi.DefaultValue ?? "nil"}";
 
 			return ret;
 		}
@@ -52,7 +52,7 @@ namespace OpenRA.Scripting
 			if (methodInfo != null)
 			{
 				var parameters = methodInfo.GetParameters().Select(pi => pi.LuaDocString());
-				return "{0} {1}({2})".F(methodInfo.ReturnType.LuaDocString(), mi.Name, parameters.JoinWith(", "));
+				return $"{methodInfo.ReturnType.LuaDocString()} {mi.Name}({parameters.JoinWith(", ")})";
 			}
 
 			var propertyInfo = mi as PropertyInfo;
@@ -64,10 +64,10 @@ namespace OpenRA.Scripting
 				if (propertyInfo.GetSetMethod() != null)
 					types.Add("set;");
 
-				return "{0} {1} {{ {2} }}".F(propertyInfo.PropertyType.LuaDocString(), mi.Name, types.JoinWith(" "));
+				return $"{propertyInfo.PropertyType.LuaDocString()} {mi.Name} {{ {types.JoinWith(" ")} }}";
 			}
 
-			return "Unknown field: {0}".F(mi.Name);
+			return $"Unknown field: {mi.Name}";
 		}
 	}
 }

OpenRA.Game/Scripting/ScriptMemberWrapper.cs

@@ -62,14 +62,14 @@ namespace OpenRA.Scripting
 					if (i >= argCount)
 					{
 						if (!pi[i].IsOptional)
-							throw new LuaException("Argument '{0}' of '{1}' is not optional.".F(pi[i].LuaDocString(), Member.LuaDocString()));
+							throw new LuaException($"Argument '{pi[i].LuaDocString()}' of '{Member.LuaDocString()}' is not optional.");
 
 						clrArgs[i] = pi[i].DefaultValue;
 						continue;
 					}
 
 					if (!args[i].TryGetClrValue(pi[i].ParameterType, out clrArgs[i]))
-						throw new LuaException("Unable to convert parameter {0} to {1}".F(i, pi[i].ParameterType.Name));
+						throw new LuaException($"Unable to convert parameter {i} to {pi[i].ParameterType.Name}");
 				}
 
 				return mi.Invoke(Target, clrArgs).ToLuaValue(context);
@@ -105,7 +105,7 @@ namespace OpenRA.Scripting
 			if (IsGetProperty)
 				return ((PropertyInfo)Member).GetValue(Target, null).ToLuaValue(context);
 
-			throw new LuaException("The property '{0}' is write-only".F(Member.Name));
+			throw new LuaException($"The property '{Member.Name}' is write-only");
 		}
 
 		public void Set(LuaRuntime runtime, LuaValue value)
@@ -114,12 +114,12 @@ namespace OpenRA.Scripting
 			{
 				var pi = (PropertyInfo)Member;
 				if (!value.TryGetClrValue(pi.PropertyType, out var clrValue))
-					throw new LuaException("Unable to convert '{0}' to Clr type '{1}'".F(value.WrappedClrType().Name, pi.PropertyType));
+					throw new LuaException($"Unable to convert '{value.WrappedClrType().Name}' to Clr type '{pi.PropertyType}'");
 
 				pi.SetValue(Target, clrValue, null);
 			}
 			else
-				throw new LuaException("The property '{0}' is read-only".F(Member.Name));
+				throw new LuaException($"The property '{Member.Name}' is read-only");
 		}
 
 		public static IEnumerable<MemberInfo> WrappableMembers(Type t)

OpenRA.Game/Scripting/ScriptPlayerInterface.cs

@@ -18,8 +18,8 @@ namespace OpenRA.Scripting
 	{
 		readonly Player player;
 
-		protected override string DuplicateKeyError(string memberName) { return "Player '{0}' defines the command '{1}' on multiple traits".F(player.PlayerName, memberName); }
+		protected override string DuplicateKeyError(string memberName) { return $"Player '{player.PlayerName}' defines the command '{memberName}' on multiple traits"; }
-		protected override string MemberNotFoundError(string memberName) { return "Player '{0}' does not define a property '{1}'".F(player.PlayerName, memberName); }
+		protected override string MemberNotFoundError(string memberName) { return $"Player '{player.PlayerName}' does not define a property '{memberName}'"; }
 
 		public ScriptPlayerInterface(ScriptContext context, Player player)
 			: base(context)

OpenRA.Game/Scripting/ScriptTypes.cs

@@ -126,7 +126,7 @@ namespace OpenRA.Scripting
 							if (!elementHasClrValue || !(element is LuaValue))
 								kv.Value.Dispose();
 							if (!elementHasClrValue)
-								throw new LuaException("Unable to convert table value of type {0} to type {1}".F(kv.Value.WrappedClrType(), innerType));
+								throw new LuaException($"Unable to convert table value of type {kv.Value.WrappedClrType()} to type {innerType}");
 						}
 
 						array.SetValue(element, i++);
@@ -186,7 +186,7 @@ namespace OpenRA.Scripting
 				return table;
 			}
 
-			throw new InvalidOperationException("Cannot convert type '{0}' to Lua. Class must implement IScriptBindable.".F(obj.GetType()));
+			throw new InvalidOperationException($"Cannot convert type '{obj.GetType()}' to Lua. Class must implement IScriptBindable.");
 		}
 	}
 }

OpenRA.Game/Server/Server.cs

@@ -494,7 +494,7 @@ namespace OpenRA.Server
 				if (bans.Contains(client.IPAddress))
 				{
 					Log.Write("server", "Rejected connection from {0}; Banned.", newConn.Socket.RemoteEndPoint);
-					SendOrderTo(newConn, "ServerError", "You have been {0} from the server".F(Settings.Ban.Contains(client.IPAddress) ? "banned" : "temporarily banned"));
+					SendOrderTo(newConn, "ServerError", $"You have been {(Settings.Ban.Contains(client.IPAddress) ? "banned" : "temporarily banned")} from the server");
 					DropClient(newConn);
 					return;
 				}
@@ -543,7 +543,7 @@ namespace OpenRA.Server
 							client.Name, newConn.Socket.RemoteEndPoint);
 
 						// Report to all other players
-						SendMessage("{0} has joined the game.".F(client.Name), newConn);
+						SendMessage($"{client.Name} has joined the game.", newConn);
 
 						// Send initial ping
 						SendOrderTo(newConn, "Ping", Game.RunTime.ToString(CultureInfo.InvariantCulture));
@@ -816,7 +816,7 @@ namespace OpenRA.Server
 					if (data.Length == Order.SyncHashOrderLength)
 						HandleSyncOrder(frame, data);
 					else
-						Log.Write("server", "Dropped sync order with length {0} from client {1}. Expected length {2}.".F(data.Length, from, Order.SyncHashOrderLength));
+						Log.Write("server", $"Dropped sync order with length {data.Length} from client {from}. Expected length {Order.SyncHashOrderLength}.");
 				}
 			}
 		}
@@ -860,7 +860,7 @@ namespace OpenRA.Server
 			DispatchOrdersToClients(conn, 0, Order.FromTargetString("Message", text, true).Serialize());
 
 			if (Type == ServerType.Dedicated)
-				Console.WriteLine("[{0}] {1}".F(DateTime.Now.ToString(Settings.TimestampFormat), text));
+				Console.WriteLine($"[{DateTime.Now.ToString(Settings.TimestampFormat)}] {text}");
 		}
 
 		void InterpretServerOrder(Connection conn, Order o)
@@ -894,7 +894,7 @@ namespace OpenRA.Server
 							if (handledBy == null)
 							{
 								Log.Write("server", "Unknown server command: {0}", o.TargetString);
-								SendOrderTo(conn, "Message", "Unknown server command: {0}".F(o.TargetString));
+								SendOrderTo(conn, "Message", $"Unknown server command: {o.TargetString}");
 							}
 
 							break;
@@ -1070,8 +1070,8 @@ namespace OpenRA.Server
 
 					var suffix = "";
 					if (State == ServerState.GameStarted)
-						suffix = dropClient.IsObserver ? " (Spectator)" : dropClient.Team != 0 ? " (Team {0})".F(dropClient.Team) : "";
+						suffix = dropClient.IsObserver ? " (Spectator)" : dropClient.Team != 0 ? $" (Team {dropClient.Team})" : "";
-					SendMessage("{0}{1} has disconnected.".F(dropClient.Name, suffix));
+					SendMessage($"{dropClient.Name}{suffix} has disconnected.");
 
 					// Send disconnected order, even if still in the lobby
 					DispatchOrdersToClients(toDrop, 0, Order.FromTargetString("Disconnected", "", true).Serialize());
@@ -1098,7 +1098,7 @@ namespace OpenRA.Server
 						if (nextAdmin != null)
 						{
 							nextAdmin.IsAdmin = true;
-							SendMessage("{0} is now the admin.".F(nextAdmin.Name));
+							SendMessage($"{nextAdmin.Name} is now the admin.");
 						}
 					}
 

OpenRA.Game/Settings.cs

@@ -304,7 +304,7 @@ namespace OpenRA
 			var err2 = FieldLoader.InvalidValueAction;
 			try
 			{
-				FieldLoader.UnknownFieldAction = (s, f) => Console.WriteLine("Ignoring unknown field `{0}` on `{1}`".F(s, f.Name));
+				FieldLoader.UnknownFieldAction = (s, f) => Console.WriteLine($"Ignoring unknown field `{s}` on `{f.Name}`");
 
 				if (File.Exists(settingsFile))
 				{
@@ -430,7 +430,7 @@ namespace OpenRA
 			FieldLoader.InvalidValueAction = (s, t, f) =>
 			{
 				var ret = defaults.GetType().GetField(f).GetValue(defaults);
-				Console.WriteLine("FieldLoader: Cannot parse `{0}` into `{2}:{1}`; substituting default `{3}`".F(s, t.Name, f, ret));
+				Console.WriteLine($"FieldLoader: Cannot parse `{s}` into `{f}:{t.Name}`; substituting default `{ret}`");
 				return ret;
 			};
 

OpenRA.Game/Sound/Sound.cs

@@ -353,14 +353,14 @@ namespace OpenRA
 			if (voicedActor != null)
 			{
 				if (!rules.VoicePools.Value.ContainsKey(definition))
-					throw new InvalidOperationException("Can't find {0} in voice pool.".F(definition));
+					throw new InvalidOperationException($"Can't find {definition} in voice pool.");
 
 				pool = rules.VoicePools.Value[definition];
 			}
 			else
 			{
 				if (!rules.NotificationsPools.Value.ContainsKey(definition))
-					throw new InvalidOperationException("Can't find {0} in notification pool.".F(definition));
+					throw new InvalidOperationException($"Can't find {definition} in notification pool.");
 
 				pool = rules.NotificationsPools.Value[definition];
 			}

OpenRA.Game/StreamExts.cs

@@ -151,7 +151,7 @@ namespace OpenRA
 		{
 			var length = s.ReadInt32();
 			if (length > maxLength)
-				throw new InvalidOperationException("The length of the string ({0}) is longer than the maximum allowed ({1}).".F(length, maxLength));
+				throw new InvalidOperationException($"The length of the string ({length}) is longer than the maximum allowed ({maxLength}).");
 
 			return encoding.GetString(s.ReadBytes(length));
 		}

OpenRA.Game/Support/Benchmark.cs

@@ -46,11 +46,11 @@ namespace OpenRA.Support
 			foreach (var sample in samples)
 			{
 				var name = sample.Key;
-				Log.AddChannel(name, "{0}{1}.csv".F(prefix, name));
+				Log.AddChannel(name, $"{prefix}{name}.csv");
 				Log.Write(name, "tick,time [ms]");
 
 				foreach (var point in sample.Value)
-					Log.Write(name, "{0},{1}".F(point.Tick,  point.Value));
+					Log.Write(name, $"{point.Tick},{point.Value}");
 			}
 		}
 

OpenRA.Game/Support/Evaluator.cs

@@ -66,7 +66,7 @@ namespace OpenRA.Support
 				else if (char.IsLetter(t[0]))
 				{
 					if (!syms.ContainsKey(t))
-						throw new InvalidOperationException("Substitution `{0}` undefined".F(t));
+						throw new InvalidOperationException($"Substitution `{t}` undefined");
 
 					yield return syms[t].ToString();
 				}

OpenRA.Game/Support/Log.cs

@@ -121,9 +121,9 @@ namespace OpenRA
 			Directory.CreateDirectory(path);
 
 			for (var i = 0; i < CreateLogFileMaxRetryCount; i++)
-				yield return Path.Combine(path, i > 0 ? "{0}.{1}".F(baseFilename, i) : baseFilename);
+				yield return Path.Combine(path, i > 0 ? $"{baseFilename}.{i}" : baseFilename);
 
-			throw new ApplicationException("Error creating log file \"{0}\"".F(baseFilename));
+			throw new ApplicationException($"Error creating log file \"{baseFilename}\"");
 		}
 
 		static ChannelInfo GetChannel(string channelName)

OpenRA.Game/Support/VariableExpression.cs

@@ -287,8 +287,7 @@ namespace OpenRA.Support
 						continue;
 				}
 
-				throw new InvalidProgramException("CreateTokenTypeInfoEnumeration is missing a TokenTypeInfo entry for TokenType.{0}".F(
+				throw new InvalidProgramException($"CreateTokenTypeInfoEnumeration is missing a TokenTypeInfo entry for TokenType.{Enum<TokenType>.GetValues()[i]}");
-					Enum<TokenType>.GetValues()[i]));
 			}
 		}
 
@@ -355,8 +354,7 @@ namespace OpenRA.Support
 						if (cc != CharClass.Digit)
 						{
 							if (cc != CharClass.Whitespace && cc != CharClass.Operator && cc != CharClass.Mixed)
-								throw new InvalidDataException("Number {0} and variable merged at index {1}".F(
+								throw new InvalidDataException($"Number {int.Parse(expression.Substring(start, i - start))} and variable merged at index {start}");
-									int.Parse(expression.Substring(start, i - start)), start));
 
 							return true;
 						}
@@ -371,8 +369,7 @@ namespace OpenRA.Support
 			static TokenType VariableOrKeyword(string expression, int start, ref int i)
 			{
 				if (CharClassOf(expression[i - 1]) == CharClass.Mixed)
-					throw new InvalidDataException("Invalid identifier end character at index {0} for `{1}`".F(
+					throw new InvalidDataException($"Invalid identifier end character at index {i - 1} for `{expression.Substring(start, i - start)}`");
-						i - 1, expression.Substring(start, i - start)));
 
 				return VariableOrKeyword(expression, start, i - start);
 			}
@@ -435,7 +432,7 @@ namespace OpenRA.Support
 							return TokenType.Equals;
 						}
 
-						throw new InvalidDataException("Unexpected character '=' at index {0} - should it be `==`?".F(start));
+						throw new InvalidDataException($"Unexpected character '=' at index {start} - should it be `==`?");
 
 					case '&':
 						i++;
@@ -445,7 +442,7 @@ namespace OpenRA.Support
 							return TokenType.And;
 						}
 
-						throw new InvalidDataException("Unexpected character '&' at index {0} - should it be `&&`?".F(start));
+						throw new InvalidDataException($"Unexpected character '&' at index {start} - should it be `&&`?");
 
 					case '|':
 						i++;
@@ -455,7 +452,7 @@ namespace OpenRA.Support
 							return TokenType.Or;
 						}
 
-						throw new InvalidDataException("Unexpected character '|' at index {0} - should it be `||`?".F(start));
+						throw new InvalidDataException($"Unexpected character '|' at index {start} - should it be `||`?");
 
 					case '(':
 						i++;
@@ -500,7 +497,7 @@ namespace OpenRA.Support
 				var cc = CharClassOf(expression[start]);
 
 				if (cc != CharClass.Id)
-					throw new InvalidDataException("Invalid character '{0}' at index {1}".F(expression[i], start));
+					throw new InvalidDataException($"Invalid character '{expression[i]}' at index {start}");
 
 				// Scan forwards until we find an invalid name character
 				for (i = start; i < expression.Length; i++)
@@ -532,15 +529,13 @@ namespace OpenRA.Support
 				else if (lastType == TokenType.Invalid)
 					whitespaceBefore = true;
 				else if (RequiresWhitespaceAfter(lastType))
-					throw new InvalidDataException("Missing whitespace at index {0}, after `{1}` operator."
+					throw new InvalidDataException($"Missing whitespace at index {i}, after `{GetTokenSymbol(lastType)}` operator.");
-						.F(i, GetTokenSymbol(lastType)));
 
 				var start = i;
 
 				var type = GetNextType(expression, ref i, lastType);
 				if (!whitespaceBefore && RequiresWhitespaceBefore(type))
-					throw new InvalidDataException("Missing whitespace at index {0}, before `{1}` operator."
+					throw new InvalidDataException($"Missing whitespace at index {i}, before `{GetTokenSymbol(type)}` operator.");
-						.F(i, GetTokenSymbol(type)));
 
 				switch (type)
 				{
@@ -602,7 +597,7 @@ namespace OpenRA.Support
 
 					// Expressions can't end with a binary or unary prefix operation
 					if (lastToken.RightOperand)
-						throw new InvalidDataException("Missing value or sub-expression at end for `{0}` operator".F(lastToken.Symbol));
+						throw new InvalidDataException($"Missing value or sub-expression at end for `{lastToken.Symbol}` operator");
 
 					break;
 				}
@@ -610,7 +605,7 @@ namespace OpenRA.Support
 				if (token.Closes != Grouping.None)
 				{
 					if (currentOpeners.Count == 0)
-						throw new InvalidDataException("Unmatched closing parenthesis at index {0}".F(token.Index));
+						throw new InvalidDataException($"Unmatched closing parenthesis at index {token.Index}");
 
 					currentOpeners.Pop();
 				}
@@ -622,22 +617,20 @@ namespace OpenRA.Support
 				{
 					// Expressions can't start with a binary or unary postfix operation or closer
 					if (token.LeftOperand)
-						throw new InvalidDataException("Missing value or sub-expression at beginning for `{0}` operator".F(token.Symbol));
+						throw new InvalidDataException($"Missing value or sub-expression at beginning for `{token.Symbol}` operator");
 				}
 				else
 				{
 					// Disallow empty parentheses
 					if (lastToken.Opens != Grouping.None && token.Closes != Grouping.None)
-						throw new InvalidDataException("Empty parenthesis at index {0}".F(lastToken.Index));
+						throw new InvalidDataException($"Empty parenthesis at index {lastToken.Index}");
 
 					// Exactly one of two consective tokens must take the other's sub-expression evaluation as an operand
 					if (lastToken.RightOperand == token.LeftOperand)
 					{
 						if (lastToken.RightOperand)
-							throw new InvalidDataException(
+							throw new InvalidDataException($"Missing value or sub-expression or there is an extra operator `{lastToken.Symbol}` at index {lastToken.Index} or `{token.Symbol}` at index {token.Index}");
-								"Missing value or sub-expression or there is an extra operator `{0}` at index {1} or `{2}` at index {3}".F(
+						throw new InvalidDataException($"Missing binary operation before `{token.Symbol}` at index {token.Index}");
-									lastToken.Symbol, lastToken.Index, token.Symbol, token.Index));
-						throw new InvalidDataException("Missing binary operation before `{0}` at index {1}".F(token.Symbol, token.Index));
 					}
 				}
 
@@ -649,7 +642,7 @@ namespace OpenRA.Support
 			}
 
 			if (currentOpeners.Count > 0)
-				throw new InvalidDataException("Unclosed opening parenthesis at index {0}".F(currentOpeners.Peek().Index));
+				throw new InvalidDataException($"Unclosed opening parenthesis at index {currentOpeners.Peek().Index}");
 
 			return new Compiler().Build(ToPostfix(tokens).ToArray(), resultType);
 		}
@@ -743,8 +736,7 @@ namespace OpenRA.Support
 						return IfThenElse(expression, One, Zero);
 				}
 
-				throw new InvalidProgramException("Unable to convert ExpressionType.{0} to ExpressionType.{1}".F(
+				throw new InvalidProgramException($"Unable to convert ExpressionType.{Enum<ExpressionType>.GetValues()[(int)fromType]} to ExpressionType.{Enum<ExpressionType>.GetValues()[(int)toType]}");
-					Enum<ExpressionType>.GetValues()[(int)fromType], Enum<ExpressionType>.GetValues()[(int)toType]));
 			}
 
 			public Expression Pop(ExpressionType type)
@@ -760,11 +752,11 @@ namespace OpenRA.Support
 				expressions.Add(expression);
 				if (type == ExpressionType.Int)
 					if (expression.Type != typeof(int))
-						throw new InvalidOperationException("Expected System.Int type instead of {0} for {1}".F(expression.Type, expression));
+						throw new InvalidOperationException($"Expected System.Int type instead of {expression.Type} for {expression}");
 
 				if (type == ExpressionType.Bool)
 					if (expression.Type != typeof(bool))
-						throw new InvalidOperationException("Expected System.Boolean type instead of {0} for {1}".F(expression.Type, expression));
+						throw new InvalidOperationException($"Expected System.Boolean type instead of {expression.Type} for {expression}");
 				types.Add(type);
 			}
 
@@ -776,7 +768,7 @@ namespace OpenRA.Support
 				else if (expression.Type == typeof(bool))
 					types.Add(ExpressionType.Bool);
 				else
-					throw new InvalidOperationException("Unhandled result type {0} for {1}".F(expression.Type, expression));
+					throw new InvalidOperationException($"Unhandled result type {expression.Type} for {expression}");
 			}
 		}
 
@@ -943,9 +935,7 @@ namespace OpenRA.Support
 						}
 
 						default:
-							throw new InvalidProgramException(
+							throw new InvalidProgramException($"ConditionExpression.Compiler.Compile() is missing an expression builder for TokenType.{Enum<TokenType>.GetValues()[(int)t.Type]}");
-								"ConditionExpression.Compiler.Compile() is missing an expression builder for TokenType.{0}".F(
-									Enum<TokenType>.GetValues()[(int)t.Type]));
 					}
 				}
 

OpenRA.Game/Sync.cs

@@ -69,14 +69,14 @@ namespace OpenRA
 				il.MarkLabel(l);
 			}
 			else if (type != typeof(int))
-				throw new NotImplementedException("SyncAttribute on member of unhashable type: {0}".F(type.FullName));
+				throw new NotImplementedException($"SyncAttribute on member of unhashable type: {type.FullName}");
 
 			il.Emit(OpCodes.Xor);
 		}
 
 		static Func<object, int> GenerateHashFunc(Type t)
 		{
-			var d = new DynamicMethod("hash_{0}".F(t.Name), typeof(int), new Type[] { typeof(object) }, t);
+			var d = new DynamicMethod($"hash_{t.Name}", typeof(int), new Type[] { typeof(object) }, t);
 			var il = d.GetILGenerator();
 			var this_ = il.DeclareLocal(t).LocalIndex;
 			il.Emit(OpCodes.Ldarg_0);

OpenRA.Game/TraitDictionary.cs

@@ -81,7 +81,7 @@ namespace OpenRA
 		static void CheckDestroyed(Actor actor)
 		{
 			if (actor.Disposed)
-				throw new InvalidOperationException("Attempted to get trait from destroyed object ({0})".F(actor));
+				throw new InvalidOperationException($"Attempted to get trait from destroyed object ({actor})");
 		}
 
 		public T Get<T>(Actor actor)
@@ -160,7 +160,7 @@ namespace OpenRA
 			{
 				var result = GetOrDefault(actor);
 				if (result == null)
-					throw new InvalidOperationException("Actor {0} does not have trait of type `{1}`".F(actor.Info.Name, typeof(T)));
+					throw new InvalidOperationException($"Actor {actor.Info.Name} does not have trait of type `{typeof(T)}`");
 
 				return result;
 			}
@@ -173,7 +173,7 @@ namespace OpenRA
 					return default;
 
 				if (index + 1 < actors.Count && actors[index + 1] == actor)
-					throw new InvalidOperationException("Actor {0} has multiple traits of type `{1}`".F(actor.Info.Name, typeof(T)));
+					throw new InvalidOperationException($"Actor {actor.Info.Name} has multiple traits of type `{typeof(T)}`");
 
 				return traits[index];
 			}

OpenRA.Game/Traits/Player/FrozenActorLayer.cs

@@ -203,7 +203,7 @@ namespace OpenRA.Traits
 
 		public override string ToString()
 		{
-			return "{0} {1}{2}".F(Info.Name, ID, IsValid ? "" : " (invalid)");
+			return $"{Info.Name} {ID}{(IsValid ? "" : " (invalid)")}";
 		}
 	}
 

OpenRA.Game/Traits/World/ScreenMap.cs

@@ -27,7 +27,7 @@ namespace OpenRA.Traits
 
 		public override int GetHashCode() { return Actor.GetHashCode() ^ Bounds.GetHashCode(); }
 
-		public override string ToString() { return "{0}->{1}".F(Actor.Info.Name, Bounds.GetType().Name); }
+		public override string ToString() { return $"{Actor.Info.Name}->{Bounds.GetType().Name}"; }
 	}
 
 	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]

OpenRA.Game/Translation.cs

@@ -104,13 +104,13 @@ namespace OpenRA
 				name = args[i] as string;
 				if (string.IsNullOrEmpty(name))
 				{
-					throw new ArgumentException("Expected the argument at index {0} to be a non-empty string".F(i),
+					throw new ArgumentException($"Expected the argument at index {i} to be a non-empty string",
 						nameof(args));
 				}
 
 				value = args[i + 1];
 				if (value == null)
-					throw new ArgumentNullException("args", "Expected the argument at index {0} to be a non-null value".F(i + 1));
+					throw new ArgumentNullException("args", $"Expected the argument at index {i + 1} to be a non-null value");
 
 				argumentDictionary.Add(name, value);
 			}

OpenRA.Game/WAngle.cs

@@ -85,7 +85,7 @@ namespace OpenRA
 		public static WAngle ArcSin(int d)
 		{
 			if (d < -1024 || d > 1024)
-				throw new ArgumentException("ArcSin is only valid for values between -1024 and 1024. Received {0}".F(d));
+				throw new ArgumentException($"ArcSin is only valid for values between -1024 and 1024. Received {d}");
 
 			var a = ClosestCosineIndex(Math.Abs(d));
 			return new WAngle(d < 0 ? 768 + a : 256 - a);
@@ -94,7 +94,7 @@ namespace OpenRA
 		public static WAngle ArcCos(int d)
 		{
 			if (d < -1024 || d > 1024)
-				throw new ArgumentException("ArcCos is only valid for values between -1024 and 1024. Received {0}".F(d));
+				throw new ArgumentException($"ArcCos is only valid for values between -1024 and 1024. Received {d}");
 
 			var a = ClosestCosineIndex(Math.Abs(d));
 			return new WAngle(d < 0 ? 512 - a : a);
@@ -222,7 +222,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out WAngle a))
-				throw new LuaException("Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			if (right.TryGetClrValue(out int c))
 			{
@@ -233,13 +233,13 @@ namespace OpenRA
 			if (right.TryGetClrValue(out WAngle b))
 				return new LuaCustomClrObject(a + b);
 
-			throw new LuaException("Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+			throw new LuaException($"Attempted to call WAngle.Add(WAngle, WAngle) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 		}
 
 		public LuaValue Subtract(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out WAngle a))
-				throw new LuaException("Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			if (right.TryGetClrValue(out int c))
 			{
@@ -250,7 +250,7 @@ namespace OpenRA
 			if (right.TryGetClrValue(out WAngle b))
 				return new LuaCustomClrObject(a - b);
 
-			throw new LuaException("Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+			throw new LuaException($"Attempted to call WAngle.Subtract(WAngle, WAngle) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 		}
 
 		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)

OpenRA.Game/WDist.cs

@@ -144,7 +144,7 @@ namespace OpenRA
 				{
 					case "Length": return Length;
 					case "Range": Game.Debug("WDist.Range is deprecated. Use WDist.Length instead"); return Length;
-					default: throw new LuaException("WDist does not define a member '{0}'".F(key));
+					default: throw new LuaException($"WDist does not define a member '{key}'");
 				}
 			}
 

OpenRA.Game/WPos.cs

@@ -83,7 +83,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out WPos a) || !right.TryGetClrValue(out WVec b))
-				throw new LuaException("Attempted to call WPos.Add(WPos, WVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call WPos.Add(WPos, WVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -92,7 +92,7 @@ namespace OpenRA
 		{
 			var rightType = right.WrappedClrType();
 			if (!left.TryGetClrValue(out WPos a))
-				throw new LuaException("Attempted to call WPos.Subtract(WPos, (WPos|WVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+				throw new LuaException($"Attempted to call WPos.Subtract(WPos, (WPos|WVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 
 			if (rightType == typeof(WPos))
 			{
@@ -105,7 +105,7 @@ namespace OpenRA
 				return new LuaCustomClrObject(a - b);
 			}
 
-			throw new LuaException("Attempted to call WPos.Subtract(WPos, (WPos|WVec)) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, rightType.Name));
+			throw new LuaException($"Attempted to call WPos.Subtract(WPos, (WPos|WVec)) with invalid arguments ({left.WrappedClrType().Name}, {rightType.Name})");
 		}
 
 		public LuaValue Equals(LuaRuntime runtime, LuaValue left, LuaValue right)
@@ -125,7 +125,7 @@ namespace OpenRA
 					case "X": return X;
 					case "Y": return Y;
 					case "Z": return Z;
-					default: throw new LuaException("WPos does not define a member '{0}'".F(key));
+					default: throw new LuaException($"WPos does not define a member '{key}'");
 				}
 			}
 

OpenRA.Game/WVec.cs

@@ -111,7 +111,7 @@ namespace OpenRA
 		public LuaValue Add(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out WVec a) || !right.TryGetClrValue(out WVec b))
-				throw new LuaException("Attempted to call WVec.Add(WVec, WVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call WVec.Add(WVec, WVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a + b);
 		}
@@ -119,7 +119,7 @@ namespace OpenRA
 		public LuaValue Subtract(LuaRuntime runtime, LuaValue left, LuaValue right)
 		{
 			if (!left.TryGetClrValue(out WVec a) || !right.TryGetClrValue(out WVec b))
-				throw new LuaException("Attempted to call WVec.Subtract(WVec, WVec) with invalid arguments ({0}, {1})".F(left.WrappedClrType().Name, right.WrappedClrType().Name));
+				throw new LuaException($"Attempted to call WVec.Subtract(WVec, WVec) with invalid arguments ({left.WrappedClrType().Name}, {right.WrappedClrType().Name})");
 
 			return new LuaCustomClrObject(a - b);
 		}
@@ -147,7 +147,7 @@ namespace OpenRA
 					case "Y": return Y;
 					case "Z": return Z;
 					case "Facing": return new LuaCustomClrObject(Yaw);
-					default: throw new LuaException("WVec does not define a member '{0}'".F(key));
+					default: throw new LuaException($"WVec does not define a member '{key}'");
 				}
 			}
 

OpenRA.Game/Widgets/Widget.cs

@@ -80,7 +80,7 @@ namespace OpenRA.Widgets
 			if (LoadWidget(id, parent, args) is T widget)
 				return widget;
 
-			throw new InvalidOperationException("Widget {0} is not of type {1}".F(id, typeof(T).Name));
+			throw new InvalidOperationException($"Widget {id} is not of type {typeof(T).Name}");
 		}
 
 		public static Widget LoadWidget(string id, Widget parent, WidgetArgs args)
@@ -236,7 +236,7 @@ namespace OpenRA.Widgets
 
 		public virtual Widget Clone()
 		{
-			throw new InvalidOperationException("Widget type `{0}` is not cloneable.".F(GetType().Name));
+			throw new InvalidOperationException($"Widget type `{GetType().Name}` is not cloneable.");
 		}
 
 		public virtual int2 RenderOrigin
@@ -579,9 +579,7 @@ namespace OpenRA.Widgets
 		{
 			var t = GetOrNull<T>(id);
 			if (t == null)
-				throw new InvalidOperationException(
+				throw new InvalidOperationException($"Widget {Id} has no child {id} of type {typeof(T).Name}");
-					"Widget {0} has no child {1} of type {2}".F(
-						Id, id, typeof(T).Name));
 			return t;
 		}
 

OpenRA.Game/Widgets/WidgetLoader.cs

@@ -30,7 +30,7 @@ namespace OpenRA
 				{
 					var key = w.Key.Substring(w.Key.IndexOf('@') + 1);
 					if (widgets.ContainsKey(key))
-						throw new InvalidDataException("Widget has duplicate Key `{0}` at {1}".F(w.Key, w.Location));
+						throw new InvalidDataException($"Widget has duplicate Key `{w.Key}` at {w.Location}");
 					widgets.Add(key, w);
 				}
 		}
@@ -38,7 +38,7 @@ namespace OpenRA
 		public Widget LoadWidget(WidgetArgs args, Widget parent, string w)
 		{
 			if (!widgets.TryGetValue(w, out var ret))
-				throw new InvalidDataException("Cannot find widget with Id `{0}`".F(w));
+				throw new InvalidDataException($"Cannot find widget with Id `{w}`");
 
 			return LoadWidget(args, parent, ret);
 		}

OpenRA.Mods.Cnc/Activities/Teleport.cs

@@ -37,7 +37,7 @@ namespace OpenRA.Mods.Cnc.Activities
 		{
 			var max = teleporter.World.Map.Grid.MaximumTileSearchRange;
 			if (maximumDistance > max)
-				throw new InvalidOperationException("Teleport distance cannot exceed the value of MaximumTileSearchRange ({0}).".F(max));
+				throw new InvalidOperationException($"Teleport distance cannot exceed the value of MaximumTileSearchRange ({max}).");
 
 			this.teleporter = teleporter;
 			this.destination = destination;

OpenRA.Mods.Cnc/FileFormats/HvaReader.cs

@@ -50,8 +50,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 					Array.Copy(Transforms, 16 * (LimbCount * j + i), testMatrix, 0, 16);
 					if (OpenRA.Graphics.Util.MatrixInverse(testMatrix) == null)
 						throw new InvalidDataException(
-							"The transformation matrix for HVA file `{0}` section {1} frame {2} is invalid because it is not invertible!"
+							$"The transformation matrix for HVA file `{fileName}` section {i} frame {j} is invalid because it is not invertible!");
-							.F(fileName, i, j));
 				}
 		}
 

OpenRA.Mods.Cnc/FileFormats/IdxEntry.cs

@@ -39,7 +39,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 
 		public override string ToString()
 		{
-			return "{0} - offset 0x{1:x8} - length 0x{2:x8}".F(Filename, Offset, Length);
+			return $"{Filename} - offset 0x{Offset:x8} - length 0x{Length:x8}";
 		}
 	}
 }

OpenRA.Mods.Cnc/FileFormats/IdxReader.cs

@@ -26,12 +26,12 @@ namespace OpenRA.Mods.Cnc.FileFormats
 			var id = s.ReadASCII(4);
 
 			if (id != "GABA")
-				throw new InvalidDataException("Unable to load Idx file, did not find magic id, found {0} instead".F(id));
+				throw new InvalidDataException($"Unable to load Idx file, did not find magic id, found {id} instead");
 
 			var two = s.ReadInt32();
 
 			if (two != 2)
-				throw new InvalidDataException("Unable to load Idx file, did not find magic number 2, found {0} instead".F(two));
+				throw new InvalidDataException($"Unable to load Idx file, did not find magic number 2, found {two} instead");
 
 			SoundCount = s.ReadInt32();
 

OpenRA.Mods.Cnc/FileFormats/LCWCompression.cs

@@ -21,7 +21,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 		static void ReplicatePrevious(byte[] dest, int destIndex, int srcIndex, int count)
 		{
 			if (srcIndex > destIndex)
-				throw new NotImplementedException("srcIndex > destIndex {0} {1}".F(srcIndex, destIndex));
+				throw new NotImplementedException($"srcIndex > destIndex {srcIndex} {destIndex}");
 
 			for (var i = 0; i < count; i++)
 			{
@@ -80,7 +80,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 						var count = count3 == 0x3F ? ctx.ReadWord() : count3 + 3;
 						var srcIndex = reverse ? destIndex - ctx.ReadWord() : ctx.ReadWord();
 						if (srcIndex >= destIndex)
-							throw new NotImplementedException("srcIndex >= destIndex {0} {1}".F(srcIndex, destIndex));
+							throw new NotImplementedException($"srcIndex >= destIndex {srcIndex} {destIndex}");
 
 						for (var end = destIndex + count; destIndex < end; destIndex++)
 							dest[destIndex] = dest[srcIndex++];

OpenRA.Mods.Cnc/FileFormats/VqaReader.cs

@@ -142,7 +142,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 					type = stream.ReadASCII(4);
 				}
 				else
-					throw new NotSupportedException("Vqa uses unknown Subtype: {0}".F(type));
+					throw new NotSupportedException($"Vqa uses unknown Subtype: {type}");
 			}
 
 			/*var length = */stream.ReadUInt16();
@@ -217,7 +217,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 							break;
 						default:
 							if (length + stream.Position > stream.Length)
-								throw new NotSupportedException("Vqa uses unknown Subtype: {0}".F(type));
+								throw new NotSupportedException($"Vqa uses unknown Subtype: {type}");
 							stream.ReadBytes((int)length);
 							break;
 					}
@@ -420,7 +420,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 						vtprSize = subchunkLength;
 						return;
 					default:
-						throw new InvalidDataException("Unknown sub-chunk {0}".F(type));
+						throw new InvalidDataException($"Unknown sub-chunk {type}");
 				}
 			}
 		}
@@ -562,7 +562,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 					// Replicate previous
 					var srcIndex = destIndex - rpos;
 					if (srcIndex > destIndex)
-						throw new NotImplementedException("srcIndex > destIndex {0} {1}".F(srcIndex, destIndex));
+						throw new NotImplementedException($"srcIndex > destIndex {srcIndex} {destIndex}");
 
 					for (var j = 0; j < count; j++)
 					{
@@ -602,7 +602,7 @@ namespace OpenRA.Mods.Cnc.FileFormats
 						var count = count3 == 0x3F ? ctx.ReadWord() : count3 + 3;
 						var srcIndex = reverse ? destIndex - ctx.ReadWord() : ctx.ReadWord();
 						if (srcIndex >= destIndex)
-							throw new NotImplementedException("srcIndex >= destIndex {0} {1}".F(srcIndex, destIndex));
+							throw new NotImplementedException($"srcIndex >= destIndex {srcIndex} {destIndex}");
 
 						for (var end = destIndex + count; destIndex < end; destIndex++)
 							dest[destIndex] = dest[srcIndex++];

OpenRA.Mods.Cnc/FileSystem/MixFile.cs

@@ -54,8 +54,8 @@ namespace OpenRA.Mods.Cnc.FileSystem
 						entries = ParseHeader(s, isCncMix ? 0 : 4, out dataStart);
 
 					index = ParseIndex(entries.ToDictionaryWithConflictLog(x => x.Hash,
-						"{0} ({1} format, Encrypted: {2}, DataStart: {3})".F(filename, isCncMix ? "C&C" : "RA/TS/RA2", isEncrypted, dataStart),
+						$"{filename} ({(isCncMix ? "C&C" : "RA/TS/RA2")} format, Encrypted: {isEncrypted}, DataStart: {dataStart})",
-						null, x => "(offs={0}, len={1})".F(x.Offset, x.Length)), allPossibleFilenames);
+						null, x => $"(offs={x.Offset}, len={x.Length})"), allPossibleFilenames);
 				}
 				catch (Exception)
 				{
@@ -103,7 +103,7 @@ namespace OpenRA.Mods.Cnc.FileSystem
 
 				var unknown = entries.Count - bestIndex.Count;
 				if (unknown > 0)
-					Log.Write("debug", "{0}: failed to resolve filenames for {1} unknown hashes".F(Name, unknown));
+					Log.Write("debug", $"{Name}: failed to resolve filenames for {unknown} unknown hashes");
 
 				return bestIndex;
 			}
@@ -165,7 +165,7 @@ namespace OpenRA.Mods.Cnc.FileSystem
 					throw new ArgumentOutOfRangeException(nameof(count), "Non-negative number required.");
 
 				if (offset + (count * 2) > s.Length)
-					throw new ArgumentException("Bytes to read {0} and offset {1} greater than stream length {2}.".F(count * 2, offset, s.Length));
+					throw new ArgumentException($"Bytes to read {count * 2} and offset {offset} greater than stream length {s.Length}.");
 
 				s.Seek(offset, SeekOrigin.Begin);
 

OpenRA.Mods.Cnc/FileSystem/PackageEntry.cs

@@ -50,9 +50,9 @@ namespace OpenRA.Mods.Cnc.FileSystem
 		public override string ToString()
 		{
 			if (names.TryGetValue(Hash, out var filename))
-				return "{0} - offset 0x{1:x8} - length 0x{2:x8}".F(filename, Offset, Length);
+				return $"{filename} - offset 0x{Offset:x8} - length 0x{Length:x8}";
 			else
-				return "0x{0:x8} - offset 0x{1:x8} - length 0x{2:x8}".F(Hash, Offset, Length);
+				return $"0x{Hash:x8} - offset 0x{Offset:x8} - length 0x{Length:x8}";
 		}
 
 		public static uint HashFilename(string name, PackageHashType type)
@@ -93,7 +93,7 @@ namespace OpenRA.Mods.Cnc.FileSystem
 						return CRC32.Calculate(Encoding.ASCII.GetBytes(name));
 					}
 
-				default: throw new NotImplementedException("Unknown hash type `{0}`".F(type));
+				default: throw new NotImplementedException($"Unknown hash type `{type}`");
 			}
 		}
 

OpenRA.Mods.Cnc/Graphics/ClassicSpriteSequence.cs

@@ -38,8 +38,7 @@ namespace OpenRA.Mods.Cnc.Graphics
 
 			if (useClassicFacings && Facings != 32)
 				throw new InvalidOperationException(
-					"{0}: Sequence {1}.{2}: UseClassicFacings is only valid for 32 facings"
+					$"{info.Nodes[0].Location}: Sequence {sequence}.{animation}: UseClassicFacings is only valid for 32 facings");
-					.F(info.Nodes[0].Location, sequence, animation));
 		}
 
 		protected override int GetFacingFrameOffset(WAngle facing)

OpenRA.Mods.Cnc/Graphics/Voxel.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Cnc.Graphics
 		public Voxel(VoxelLoader loader, VxlReader vxl, HvaReader hva, (string Vxl, string Hva) files)
 		{
 			if (vxl.LimbCount != hva.LimbCount)
-				throw new InvalidOperationException("{0}.vxl and {1}.hva limb counts don't match.".F(files.Vxl, files.Hva));
+				throw new InvalidOperationException($"{files.Vxl}.vxl and {files.Hva}.hva limb counts don't match.");
 
 			transforms = hva.Transforms;
 			frames = hva.FrameCount;
@@ -60,9 +60,9 @@ namespace OpenRA.Mods.Cnc.Graphics
 		public float[] TransformationMatrix(uint limb, uint frame)
 		{
 			if (frame >= frames)
-				throw new ArgumentOutOfRangeException(nameof(frame), "Only {0} frames exist.".F(frames));
+				throw new ArgumentOutOfRangeException(nameof(frame), $"Only {frames} frames exist.");
 			if (limb >= limbs)
-				throw new ArgumentOutOfRangeException(nameof(limb), "Only {1} limbs exist.".F(limbs));
+				throw new ArgumentOutOfRangeException(nameof(limb), $"Only {limbs} limbs exist.");
 
 			var l = limbData[limb];
 			var t = new float[16];

OpenRA.Mods.Cnc/Graphics/VoxelModelSequenceLoader.cs

@@ -98,10 +98,10 @@ namespace OpenRA.Mods.Cnc.Graphics
 			{
 				if (models.ContainsKey(model))
 					throw new InvalidOperationException(
-						"Model `{0}` does not have a sequence `{1}`".F(model, sequence));
+						$"Model `{model}` does not have a sequence `{sequence}`");
 				else
 					throw new InvalidOperationException(
-						"Model `{0}` does not have any sequences defined.".F(model));
+						$"Model `{model}` does not have any sequences defined.");
 			}
 		}
 
@@ -109,7 +109,7 @@ namespace OpenRA.Mods.Cnc.Graphics
 		{
 			if (!models.ContainsKey(model))
 				throw new InvalidOperationException(
-					"Model `{0}` does not have any sequences defined.".F(model));
+					$"Model `{model}` does not have any sequences defined.");
 
 			return models[model].ContainsKey(sequence);
 		}

OpenRA.Mods.Cnc/Scripting/Properties/ChronosphereProperties.cs

@@ -33,8 +33,7 @@ namespace OpenRA.Mods.Cnc.Scripting
 				using (kv.Value)
 				{
 					if (!kv.Key.TryGetClrValue(out actor) || !kv.Value.TryGetClrValue(out cell))
-						throw new LuaException("Chronoshift requires a table of Actor,CPos pairs. Received {0},{1}".F(
+						throw new LuaException($"Chronoshift requires a table of Actor,CPos pairs. Received {kv.Key.WrappedClrType().Name},{kv.Value.WrappedClrType().Name}");
-							kv.Key.WrappedClrType().Name, kv.Value.WrappedClrType().Name));
 				}
 
 				var cs = actor.TraitsImplementing<Chronoshiftable>()

OpenRA.Mods.Cnc/Scripting/Properties/InfiltrateProperties.cs

@@ -35,7 +35,7 @@ namespace OpenRA.Mods.Cnc.Scripting
 			var infiltrates = infiltratesTraits.FirstOrDefault(x => !x.IsTraitDisabled && x.Info.Types.Overlaps(target.GetEnabledTargetTypes()));
 
 			if (infiltrates == null)
-				throw new LuaException("{0} tried to infiltrate invalid target {1}!".F(Self, target));
+				throw new LuaException($"{Self} tried to infiltrate invalid target {target}!");
 
 			// NB: Scripted actions get no visible targetlines.
 			Self.QueueActivity(new Infiltrate(Self, Target.FromActor(target), infiltrates, null));

OpenRA.Mods.Cnc/SpriteLoaders/ShpRemasteredLoader.cs

@@ -75,7 +75,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 					framePrefix = prefix;
 
 				if (prefix != framePrefix)
-					throw new InvalidDataException("Frame prefix mismatch: `{0}` != `{1}`".F(prefix, framePrefix));
+					throw new InvalidDataException($"Frame prefix mismatch: `{prefix}` != `{framePrefix}`");
 
 				frameCount = Math.Max(frameCount, int.Parse(match.Groups["frame"].Value) + 1);
 			}
@@ -83,7 +83,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 			var frames = new ISpriteFrame[frameCount];
 			for (var i = 0; i < frames.Length; i++)
 			{
-				var tgaEntry = container.GetEntry("{0}{1:D4}.tga".F(framePrefix, i));
+				var tgaEntry = container.GetEntry($"{framePrefix}{i:D4}.tga");
 
 				// Blank frame
 				if (tgaEntry == null)
@@ -92,7 +92,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 					continue;
 				}
 
-				var metaEntry = container.GetEntry("{0}{1:D4}.meta".F(framePrefix, i));
+				var metaEntry = container.GetEntry($"{framePrefix}{i:D4}.meta");
 				using (var tgaStream = container.GetInputStream(tgaEntry))
 				{
 					var metaStream = metaEntry != null ? container.GetInputStream(metaEntry) : null;

OpenRA.Mods.Cnc/SpriteLoaders/ShpTDLoader.cs

@@ -147,7 +147,7 @@ namespace OpenRA.Mods.Cnc.SpriteLoaders
 				if (h.Format == Format.XORPrev)
 					h.RefImage = headers[i - 1];
 				else if (h.Format == Format.XORLCW && !offsets.TryGetValue(h.RefOffset, out h.RefImage))
-					throw new InvalidDataException("Reference doesn't point to image data {0}->{1}".F(h.FileOffset, h.RefOffset));
+					throw new InvalidDataException($"Reference doesn't point to image data {h.FileOffset}->{h.RefOffset}");
 			}
 
 			shpBytesFileOffset = stream.Position;

OpenRA.Mods.Cnc/Traits/EnergyWall.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		{
 			var weaponToLower = Weapon.ToLowerInvariant();
 			if (!rules.Weapons.TryGetValue(weaponToLower, out var weaponInfo))
-				throw new YamlException("Weapons Ruleset does not contain an entry '{0}'".F(weaponToLower));
+				throw new YamlException($"Weapons Ruleset does not contain an entry '{weaponToLower}'");
 
 			WeaponInfo = weaponInfo;
 		}

OpenRA.Mods.Cnc/Traits/MadTank.cs

@@ -77,10 +77,10 @@ namespace OpenRA.Mods.Cnc.Traits
 			var detonationWeaponToLower = (DetonationWeapon ?? string.Empty).ToLowerInvariant();
 
 			if (!rules.Weapons.TryGetValue(thumpDamageWeaponToLower, out var thumpDamageWeapon))
-				throw new YamlException("Weapons Ruleset does not contain an entry '{0}'".F(thumpDamageWeaponToLower));
+				throw new YamlException($"Weapons Ruleset does not contain an entry '{thumpDamageWeaponToLower}'");
 
 			if (!rules.Weapons.TryGetValue(detonationWeaponToLower, out var detonationWeapon))
-				throw new YamlException("Weapons Ruleset does not contain an entry '{0}'".F(detonationWeaponToLower));
+				throw new YamlException($"Weapons Ruleset does not contain an entry '{detonationWeaponToLower}'");
 
 			ThumpDamageWeaponInfo = thumpDamageWeapon;
 			DetonationWeaponInfo = detonationWeapon;

OpenRA.Mods.Cnc/Traits/Minelayer.cs

@@ -81,8 +81,8 @@ namespace OpenRA.Mods.Cnc.Traits
 			this.self = self;
 
 			var tileset = self.World.Map.Tileset.ToLowerInvariant();
-			if (self.World.Map.Rules.Sequences.HasSequence("overlay", "{0}-{1}".F(Info.TileValidName, tileset)))
+			if (self.World.Map.Rules.Sequences.HasSequence("overlay", $"{Info.TileValidName}-{tileset}"))
-				Tile = self.World.Map.Rules.Sequences.GetSequence("overlay", "{0}-{1}".F(Info.TileValidName, tileset)).GetSprite(0);
+				Tile = self.World.Map.Rules.Sequences.GetSequence("overlay", $"{Info.TileValidName}-{tileset}").GetSprite(0);
 			else
 				Tile = self.World.Map.Rules.Sequences.GetSequence("overlay", Info.TileValidName).GetSprite(0);
 		}
@@ -220,9 +220,9 @@ namespace OpenRA.Mods.Cnc.Traits
 
 				minelayer = a.Trait<Minelayer>();
 				var tileset = a.World.Map.Tileset.ToLowerInvariant();
-				if (a.World.Map.Rules.Sequences.HasSequence("overlay", "{0}-{1}".F(minelayer.Info.TileValidName, tileset)))
+				if (a.World.Map.Rules.Sequences.HasSequence("overlay", $"{minelayer.Info.TileValidName}-{tileset}"))
 				{
-					var validSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", "{0}-{1}".F(minelayer.Info.TileValidName, tileset));
+					var validSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", $"{minelayer.Info.TileValidName}-{tileset}");
 					validTile = validSequence.GetSprite(0);
 					validAlpha = validSequence.GetAlpha(0);
 				}
@@ -233,9 +233,9 @@ namespace OpenRA.Mods.Cnc.Traits
 					validAlpha = validSequence.GetAlpha(0);
 				}
 
-				if (a.World.Map.Rules.Sequences.HasSequence("overlay", "{0}-{1}".F(minelayer.Info.TileUnknownName, tileset)))
+				if (a.World.Map.Rules.Sequences.HasSequence("overlay", $"{minelayer.Info.TileUnknownName}-{tileset}"))
 				{
-					var unknownSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", "{0}-{1}".F(minelayer.Info.TileUnknownName, tileset));
+					var unknownSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", $"{minelayer.Info.TileUnknownName}-{tileset}");
 					unknownTile = unknownSequence.GetSprite(0);
 					unknownAlpha = unknownSequence.GetAlpha(0);
 				}
@@ -246,9 +246,9 @@ namespace OpenRA.Mods.Cnc.Traits
 					unknownAlpha = unknownSequence.GetAlpha(0);
 				}
 
-				if (a.World.Map.Rules.Sequences.HasSequence("overlay", "{0}-{1}".F(minelayer.Info.TileInvalidName, tileset)))
+				if (a.World.Map.Rules.Sequences.HasSequence("overlay", $"{minelayer.Info.TileInvalidName}-{tileset}"))
 				{
-					var blockedSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", "{0}-{1}".F(minelayer.Info.TileInvalidName, tileset));
+					var blockedSequence = a.World.Map.Rules.Sequences.GetSequence("overlay", $"{minelayer.Info.TileInvalidName}-{tileset}");
 					blockedTile = blockedSequence.GetSprite(0);
 					blockedAlpha = blockedSequence.GetAlpha(0);
 				}

OpenRA.Mods.Cnc/Traits/SupportPowers/DropPodsPower.cs

@@ -68,7 +68,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		{
 			var weaponToLower = (Weapon ?? string.Empty).ToLowerInvariant();
 			if (!rules.Weapons.TryGetValue(weaponToLower, out var weapon))
-				throw new YamlException("Weapons Ruleset does not contain an entry '{0}'".F(weaponToLower));
+				throw new YamlException($"Weapons Ruleset does not contain an entry '{weaponToLower}'");
 
 			WeaponInfo = weapon;
 

OpenRA.Mods.Cnc/Traits/SupportPowers/IonCannonPower.cs

@@ -54,7 +54,7 @@ namespace OpenRA.Mods.Cnc.Traits
 		{
 			var weaponToLower = (Weapon ?? string.Empty).ToLowerInvariant();
 			if (!rules.Weapons.TryGetValue(weaponToLower, out var weapon))
-				throw new YamlException("Weapons Ruleset does not contain an entry '{0}'".F(weaponToLower));
+				throw new YamlException($"Weapons Ruleset does not contain an entry '{weaponToLower}'");
 
 			WeaponInfo = weapon;
 

OpenRA.Mods.Cnc/Traits/World/TSVeinsRenderer.cs

@@ -249,7 +249,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			else if (BorderIndices.TryGetValue(adjacency, out var indices))
 				UpdateSpriteLayers(cell, indices);
 			else
-				throw new InvalidOperationException("SpriteMap does not contain an index for Adjacency type '{0}'".F(adjacency));
+				throw new InvalidOperationException($"SpriteMap does not contain an index for Adjacency type '{adjacency}'");
 		}
 
 		void UpdateSpriteLayers(CPos cell, int[] indices)