diff --git a/OpenRA.Game/Exts.cs b/OpenRA.Game/Exts.cs
index 5a2e5591c8..7f3475cd52 100644
--- a/OpenRA.Game/Exts.cs
+++ b/OpenRA.Game/Exts.cs
@@ -135,6 +135,16 @@ namespace OpenRA
 			return Array.IndexOf(array, value);
 		}
 
+		public static T FirstOrDefault<T>(this T[] array, Predicate<T> match)
+		{
+			return Array.Find(array, match);
+		}
+
+		public static T FirstOrDefault<T>(this List<T> list, Predicate<T> match)
+		{
+			return list.Find(match);
+		}
+
 		public static T Random<T>(this IEnumerable<T> ts, MersenneTwister r)
 		{
 			return Random(ts, r, true);
diff --git a/OpenRA.Game/FileSystem/FileSystem.cs b/OpenRA.Game/FileSystem/FileSystem.cs
index 110028d3df..f6518ee173 100644
--- a/OpenRA.Game/FileSystem/FileSystem.cs
+++ b/OpenRA.Game/FileSystem/FileSystem.cs
@@ -328,7 +328,7 @@ namespace OpenRA.FileSystem
 				if (name == ".")
 					continue;
 
-				resolved = Array.Find(Directory.GetFileSystemEntries(resolved), e => e.Equals(Path.Combine(resolved, name), StringComparison.InvariantCultureIgnoreCase));
+				resolved = Directory.GetFileSystemEntries(resolved).FirstOrDefault(e => e.Equals(Path.Combine(resolved, name), StringComparison.InvariantCultureIgnoreCase));
 
 				if (resolved == null)
 					return null;
diff --git a/OpenRA.Game/Network/UnitOrders.cs b/OpenRA.Game/Network/UnitOrders.cs
index 837ddf5190..a2e365b1ad 100644
--- a/OpenRA.Game/Network/UnitOrders.cs
+++ b/OpenRA.Game/Network/UnitOrders.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Server;
@@ -43,7 +42,7 @@ namespace OpenRA.Network
 
 		static Player FindPlayerByClient(this World world, Session.Client c)
 		{
-			return Array.Find(world.Players, p => p.ClientIndex == c.Index && p.PlayerReference.Playable);
+			return world.Players.FirstOrDefault(p => p.ClientIndex == c.Index && p.PlayerReference.Playable);
 		}
 
 		static bool OrderNotFromServerOrWorldIsReplay(int clientId, World world) => clientId != 0 || (world != null && world.IsReplay);
@@ -185,12 +184,12 @@ namespace OpenRA.Network
 					if (!string.IsNullOrEmpty(order.TargetString))
 					{
 						var data = MiniYaml.FromString(order.TargetString);
-						var saveLastOrdersFrame = data.Find(n => n.Key == "SaveLastOrdersFrame");
+						var saveLastOrdersFrame = data.FirstOrDefault(n => n.Key == "SaveLastOrdersFrame");
 						if (saveLastOrdersFrame != null)
 							orderManager.GameSaveLastFrame =
 								FieldLoader.GetValue<int>("saveLastOrdersFrame", saveLastOrdersFrame.Value.Value);
 
-						var saveSyncFrame = data.Find(n => n.Key == "SaveSyncFrame");
+						var saveSyncFrame = data.FirstOrDefault(n => n.Key == "SaveSyncFrame");
 						if (saveSyncFrame != null)
 							orderManager.GameSaveLastSyncFrame =
 								FieldLoader.GetValue<int>("SaveSyncFrame", saveSyncFrame.Value.Value);
@@ -375,7 +374,7 @@ namespace OpenRA.Network
 						var strings = node.Key.Split('@');
 						if (strings[0] == "ConnectionQuality")
 						{
-							var client = orderManager.LobbyInfo.Clients.Find(c => c.Index == Exts.ParseInt32Invariant(strings[1]));
+							var client = orderManager.LobbyInfo.Clients.FirstOrDefault(c => c.Index == Exts.ParseInt32Invariant(strings[1]));
 							if (client != null)
 								client.ConnectionQuality = FieldLoader.GetValue<Session.ConnectionQuality>("ConnectionQuality", node.Value.Value);
 						}
diff --git a/OpenRA.Game/Player.cs b/OpenRA.Game/Player.cs
index 36602f14a7..20ba3c35fe 100644
--- a/OpenRA.Game/Player.cs
+++ b/OpenRA.Game/Player.cs
@@ -109,14 +109,14 @@ namespace OpenRA
 				.Where(f => !requireSelectable || f.Selectable)
 				.ToList();
 
-			var selected = selectableFactions.Find(f => f.InternalName == factionName)
+			var selected = selectableFactions.FirstOrDefault(f => f.InternalName == factionName)
 				?? selectableFactions.Random(playerRandom);
 
 			// Don't loop infinite
 			for (var i = 0; i <= 10 && selected.RandomFactionMembers.Count > 0; i++)
 			{
 				var faction = selected.RandomFactionMembers.Random(playerRandom);
-				selected = selectableFactions.Find(f => f.InternalName == faction);
+				selected = selectableFactions.FirstOrDefault(f => f.InternalName == faction);
 
 				if (selected == null)
 					throw new YamlException($"Unknown faction: {faction}");
@@ -179,7 +179,7 @@ namespace OpenRA
 			else
 			{
 				// Map player
-				ClientIndex = world.LobbyInfo.Clients.Find(c => c.IsAdmin)?.Index ?? 0; // Owned by the host (TODO: fix this)
+				ClientIndex = world.LobbyInfo.Clients.FirstOrDefault(c => c.IsAdmin)?.Index ?? 0; // Owned by the host (TODO: fix this)
 				Color = pr.Color;
 				PlayerName = pr.Name;
 				NonCombatant = pr.NonCombatant;
diff --git a/OpenRA.Game/Scripting/ScriptContext.cs b/OpenRA.Game/Scripting/ScriptContext.cs
index e43f22279b..3b53051c1a 100644
--- a/OpenRA.Game/Scripting/ScriptContext.cs
+++ b/OpenRA.Game/Scripting/ScriptContext.cs
@@ -211,7 +211,7 @@ namespace OpenRA.Scripting
 			var bindings = Game.ModData.ObjectCreator.GetTypesImplementing<ScriptGlobal>();
 			foreach (var b in bindings)
 			{
-				var ctor = Array.Find(b.GetConstructors(BindingFlags.Public | BindingFlags.Instance), c =>
+				var ctor = b.GetConstructors(BindingFlags.Public | BindingFlags.Instance).FirstOrDefault(c =>
 				{
 					var p = c.GetParameters();
 					return p.Length == 1 && p[0].ParameterType == typeof(ScriptContext);
diff --git a/OpenRA.Game/Server/Server.cs b/OpenRA.Game/Server/Server.cs
index 0d15a2ff3b..2eadac0ea7 100644
--- a/OpenRA.Game/Server/Server.cs
+++ b/OpenRA.Game/Server/Server.cs
@@ -1160,7 +1160,7 @@ namespace OpenRA.Server
 		}
 
 		public bool HasClientWonOrLost(Session.Client client) =>
-			worldPlayers.Find(p => p?.ClientIndex == client.Index)?.Outcome != WinState.Undefined;
+			worldPlayers.FirstOrDefault(p => p?.ClientIndex == client.Index)?.Outcome != WinState.Undefined;
 
 		public void DropClient(Connection toDrop)
 		{
@@ -1169,7 +1169,7 @@ namespace OpenRA.Server
 				orderBuffer?.RemovePlayer(toDrop.PlayerIndex);
 				Conns.Remove(toDrop);
 
-				var dropClient = LobbyInfo.Clients.Find(c => c.Index == toDrop.PlayerIndex);
+				var dropClient = LobbyInfo.Clients.FirstOrDefault(c => c.Index == toDrop.PlayerIndex);
 				if (dropClient == null)
 				{
 					toDrop.Dispose();
diff --git a/OpenRA.Game/Settings.cs b/OpenRA.Game/Settings.cs
index c11e499627..1ff0c955f9 100644
--- a/OpenRA.Game/Settings.cs
+++ b/OpenRA.Game/Settings.cs
@@ -348,7 +348,7 @@ namespace OpenRA
 							LoadSectionYaml(yamlSection.Value, settingsSection);
 					}
 
-					var keysNode = yamlCache.Find(n => n.Key == "Keys");
+					var keysNode = yamlCache.FirstOrDefault(n => n.Key == "Keys");
 					if (keysNode != null)
 						foreach (var node in keysNode.Value.Nodes)
 							if (node.Key != null)
@@ -373,7 +373,7 @@ namespace OpenRA
 			var yamlCacheBuilder = yamlCache.ConvertAll(n => new MiniYamlNodeBuilder(n));
 			foreach (var kv in Sections)
 			{
-				var sectionYaml = yamlCacheBuilder.Find(x => x.Key == kv.Key);
+				var sectionYaml = yamlCacheBuilder.FirstOrDefault(x => x.Key == kv.Key);
 				if (sectionYaml == null)
 				{
 					sectionYaml = new MiniYamlNodeBuilder(kv.Key, new MiniYamlBuilder(""));
@@ -403,7 +403,7 @@ namespace OpenRA
 				}
 			}
 
-			var keysYaml = yamlCacheBuilder.Find(x => x.Key == "Keys");
+			var keysYaml = yamlCacheBuilder.FirstOrDefault(x => x.Key == "Keys");
 			if (keysYaml == null)
 			{
 				keysYaml = new MiniYamlNodeBuilder("Keys", new MiniYamlBuilder(""));
diff --git a/OpenRA.Mods.Cnc/Scripting/Properties/InfiltrateProperties.cs b/OpenRA.Mods.Cnc/Scripting/Properties/InfiltrateProperties.cs
index 11ee26e5b8..e9d8a646b1 100644
--- a/OpenRA.Mods.Cnc/Scripting/Properties/InfiltrateProperties.cs
+++ b/OpenRA.Mods.Cnc/Scripting/Properties/InfiltrateProperties.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Linq;
 using Eluant;
 using OpenRA.Mods.Cnc.Activities;
@@ -33,7 +32,7 @@ namespace OpenRA.Mods.Cnc.Scripting
 		[Desc("Infiltrate the target actor.")]
 		public void Infiltrate(Actor target)
 		{
-			var infiltrates = Array.Find(infiltratesTraits, x => !x.IsTraitDisabled && x.Info.Types.Overlaps(target.GetEnabledTargetTypes()));
+			var infiltrates = infiltratesTraits.FirstOrDefault(x => !x.IsTraitDisabled && x.Info.Types.Overlaps(target.GetEnabledTargetTypes()));
 
 			if (infiltrates == null)
 				throw new LuaException($"{Self} tried to infiltrate invalid target {target}!");
diff --git a/OpenRA.Mods.Cnc/Traits/SupportPowers/GrantPrerequisiteChargeDrainPower.cs b/OpenRA.Mods.Cnc/Traits/SupportPowers/GrantPrerequisiteChargeDrainPower.cs
index 0cb1749955..553c005495 100644
--- a/OpenRA.Mods.Cnc/Traits/SupportPowers/GrantPrerequisiteChargeDrainPower.cs
+++ b/OpenRA.Mods.Cnc/Traits/SupportPowers/GrantPrerequisiteChargeDrainPower.cs
@@ -161,7 +161,7 @@ namespace OpenRA.Mods.Cnc.Traits
 				if (!available || order.ExtraData != 1)
 					return;
 
-				var power = Instances.Find(i => !i.IsTraitPaused);
+				var power = Instances.FirstOrDefault(i => !i.IsTraitPaused);
 				if (power == null)
 					return;
 
diff --git a/OpenRA.Mods.Common/Activities/LayMines.cs b/OpenRA.Mods.Common/Activities/LayMines.cs
index 0fc25b4764..fb5740af16 100644
--- a/OpenRA.Mods.Common/Activities/LayMines.cs
+++ b/OpenRA.Mods.Common/Activities/LayMines.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Activities;
@@ -176,7 +175,7 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			if (ammoPools != null)
 			{
-				var pool = Array.Find(ammoPools, x => x.Info.Name == minelayer.Info.AmmoPoolName);
+				var pool = ammoPools.FirstOrDefault(x => x.Info.Name == minelayer.Info.AmmoPoolName);
 				if (pool == null)
 					return false;
 
@@ -194,7 +193,7 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			if (ammoPools != null)
 			{
-				var pool = Array.Find(ammoPools, x => x.Info.Name == minelayer.Info.AmmoPoolName);
+				var pool = ammoPools.FirstOrDefault(x => x.Info.Name == minelayer.Info.AmmoPoolName);
 				if (pool == null)
 					return false;
 
diff --git a/OpenRA.Mods.Common/Activities/Resupply.cs b/OpenRA.Mods.Common/Activities/Resupply.cs
index 3b5478fb14..f8316f08ed 100644
--- a/OpenRA.Mods.Common/Activities/Resupply.cs
+++ b/OpenRA.Mods.Common/Activities/Resupply.cs
@@ -141,7 +141,7 @@ namespace OpenRA.Mods.Common.Activities
 					QueueChild(move.MoveWithinRange(host, closeEnough, targetLineColor: moveInfo.GetTargetLineColor()));
 
 				var delta = (self.CenterPosition - host.CenterPosition).LengthSquared;
-				Array.Find(transportCallers, t => t.MinimumDistance.LengthSquared < delta)?.RequestTransport(self, targetCell);
+				transportCallers.FirstOrDefault(t => t.MinimumDistance.LengthSquared < delta)?.RequestTransport(self, targetCell);
 
 				return false;
 			}
@@ -256,7 +256,7 @@ namespace OpenRA.Mods.Common.Activities
 
 		void RepairTick(Actor self)
 		{
-			var repairsUnits = Array.Find(allRepairsUnits, r => !r.IsTraitDisabled && !r.IsTraitPaused);
+			var repairsUnits = allRepairsUnits.FirstOrDefault(r => !r.IsTraitDisabled && !r.IsTraitPaused);
 			if (repairsUnits == null)
 			{
 				if (!allRepairsUnits.Any(r => r.IsTraitPaused))
diff --git a/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs b/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs
index 96870efd5a..3990bf8eed 100644
--- a/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs
+++ b/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs
@@ -89,7 +89,7 @@ namespace OpenRA.Mods.Common.FileFormats
 
 		public void ExtractFile(string filename, Stream output, Action<int> onProgress = null)
 		{
-			var file = Array.Find(files, f => f.FileName == filename);
+			var file = files.FirstOrDefault(f => f.FileName == filename);
 			if (file == null)
 				throw new FileNotFoundException(filename);
 
diff --git a/OpenRA.Mods.Common/Lint/CheckTranslationReference.cs b/OpenRA.Mods.Common/Lint/CheckTranslationReference.cs
index 4967629398..cb954911e0 100644
--- a/OpenRA.Mods.Common/Lint/CheckTranslationReference.cs
+++ b/OpenRA.Mods.Common/Lint/CheckTranslationReference.cs
@@ -207,7 +207,7 @@ namespace OpenRA.Mods.Common.Lint
 					continue;
 
 				var childType = childNode.Key.Split('@')[0];
-				var field = Array.Find(translationNodes, t => t.Name == childType);
+				var field = translationNodes.FirstOrDefault(t => t.Name == childType);
 				if (field.Name == null)
 					continue;
 
diff --git a/OpenRA.Mods.Common/Scripting/Global/PlayerGlobal.cs b/OpenRA.Mods.Common/Scripting/Global/PlayerGlobal.cs
index 4ceca1a3f9..cd41a413a7 100644
--- a/OpenRA.Mods.Common/Scripting/Global/PlayerGlobal.cs
+++ b/OpenRA.Mods.Common/Scripting/Global/PlayerGlobal.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Linq;
 using Eluant;
 using OpenRA.Scripting;
@@ -25,7 +24,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Returns the player with the specified internal name, or nil if a match is not found.")]
 		public Player GetPlayer(string name)
 		{
-			return Array.Find(Context.World.Players, p => p.InternalName == name);
+			return Context.World.Players.FirstOrDefault(p => p.InternalName == name);
 		}
 
 		[Desc("Returns a table of players filtered by the specified function.")]
diff --git a/OpenRA.Mods.Common/Scripting/Properties/AmmoPoolProperties.cs b/OpenRA.Mods.Common/Scripting/Properties/AmmoPoolProperties.cs
index 9c63ddfbf0..3b7d3b73bf 100644
--- a/OpenRA.Mods.Common/Scripting/Properties/AmmoPoolProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/AmmoPoolProperties.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Linq;
 using Eluant;
 using OpenRA.Mods.Common.Traits;
@@ -34,7 +33,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Returns the count of the actor's specified ammopool.")]
 		public int AmmoCount(string poolName = "primary")
 		{
-			var pool = Array.Find(ammoPools, a => a.Info.Name == poolName);
+			var pool = ammoPools.FirstOrDefault(a => a.Info.Name == poolName);
 			if (pool == null)
 				throw new LuaException($"Invalid ammopool name {poolName} queried on actor {self}.");
 
@@ -44,7 +43,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Returns the maximum count of ammo the actor can load.")]
 		public int MaximumAmmoCount(string poolName = "primary")
 		{
-			var pool = Array.Find(ammoPools, a => a.Info.Name == poolName);
+			var pool = ammoPools.FirstOrDefault(a => a.Info.Name == poolName);
 			if (pool == null)
 				throw new LuaException($"Invalid ammopool name {poolName} queried on actor {self}.");
 
@@ -55,7 +54,7 @@ namespace OpenRA.Mods.Common.Scripting
 			"(Use a negative amount to remove ammo.)")]
 		public void Reload(string poolName = "primary", int amount = 1)
 		{
-			var pool = Array.Find(ammoPools, a => a.Info.Name == poolName);
+			var pool = ammoPools.FirstOrDefault(a => a.Info.Name == poolName);
 			if (pool == null)
 				throw new LuaException($"Invalid ammopool name {poolName} queried on actor {self}.");
 
diff --git a/OpenRA.Mods.Common/Scripting/Properties/ConditionProperties.cs b/OpenRA.Mods.Common/Scripting/Properties/ConditionProperties.cs
index a2da37bdd6..c16d46943e 100644
--- a/OpenRA.Mods.Common/Scripting/Properties/ConditionProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/ConditionProperties.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Linq;
 using Eluant;
 using OpenRA.Mods.Common.Traits;
@@ -34,7 +33,7 @@ namespace OpenRA.Mods.Common.Scripting
 			"If duration > 0 the condition will be automatically revoked after the defined number of ticks.")]
 		public int GrantCondition(string condition, int duration = 0)
 		{
-			var external = Array.Find(externalConditions, t => t.Info.Condition == condition && t.CanGrantCondition(this));
+			var external = externalConditions.FirstOrDefault(t => t.Info.Condition == condition && t.CanGrantCondition(this));
 
 			if (external == null)
 				throw new LuaException($"Condition `{condition}` has not been listed on an enabled ExternalCondition trait");
diff --git a/OpenRA.Mods.Common/Scripting/Properties/PlayerConditionProperties.cs b/OpenRA.Mods.Common/Scripting/Properties/PlayerConditionProperties.cs
index 280fe19588..328f2641dc 100644
--- a/OpenRA.Mods.Common/Scripting/Properties/PlayerConditionProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/PlayerConditionProperties.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Linq;
 using Eluant;
 using OpenRA.Mods.Common.Traits;
@@ -33,7 +32,7 @@ namespace OpenRA.Mods.Common.Scripting
 			"If duration > 0 the condition will be automatically revoked after the defined number of ticks.")]
 		public int GrantCondition(string condition, int duration = 0)
 		{
-			var external = Array.Find(externalConditions, t => t.Info.Condition == condition && t.CanGrantCondition(this));
+			var external = externalConditions.FirstOrDefault(t => t.Info.Condition == condition && t.CanGrantCondition(this));
 
 			if (external == null)
 				throw new LuaException($"Condition `{condition}` has not been listed on an enabled ExternalCondition trait");
diff --git a/OpenRA.Mods.Common/Scripting/Properties/PlayerProperties.cs b/OpenRA.Mods.Common/Scripting/Properties/PlayerProperties.cs
index eeb645376c..8b62a6fb86 100644
--- a/OpenRA.Mods.Common/Scripting/Properties/PlayerProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/PlayerProperties.cs
@@ -47,7 +47,7 @@ namespace OpenRA.Mods.Common.Scripting
 		{
 			get
 			{
-				var c = Player.World.LobbyInfo.Clients.Find(i => i.Index == Player.ClientIndex);
+				var c = Player.World.LobbyInfo.Clients.FirstOrDefault(i => i.Index == Player.ClientIndex);
 				return c?.Team ?? 0;
 			}
 		}
@@ -57,7 +57,7 @@ namespace OpenRA.Mods.Common.Scripting
 		{
 			get
 			{
-				var c = Player.World.LobbyInfo.Clients.Find(i => i.Index == Player.ClientIndex);
+				var c = Player.World.LobbyInfo.Clients.FirstOrDefault(i => i.Index == Player.ClientIndex);
 				return c?.Handicap ?? 0;
 			}
 		}
diff --git a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
index b7185e63cf..3c2bbf87a8 100644
--- a/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
+++ b/OpenRA.Mods.Common/ServerTraits/LobbyCommands.cs
@@ -278,7 +278,7 @@ namespace OpenRA.Mods.Common.Server
 				{
 					// Client 0 will always be the Host
 					// In some cases client 0 doesn't exist, so we untick all players
-					var host = server.LobbyInfo.Clients.Find(c => c.Index == 0);
+					var host = server.LobbyInfo.Clients.FirstOrDefault(c => c.Index == 0);
 					if (host != null)
 						host.State = Session.ClientState.NotReady;
 					else
@@ -442,7 +442,7 @@ namespace OpenRA.Mods.Common.Server
 					}
 					else
 					{
-						var occupantConn = server.Conns.Find(c => c.PlayerIndex == occupant.Index);
+						var occupantConn = server.Conns.FirstOrDefault(c => c.PlayerIndex == occupant.Index);
 						if (occupantConn != null)
 						{
 							server.SendOrderTo(conn, "ServerError", SlotClosed);
@@ -1143,7 +1143,7 @@ namespace OpenRA.Mods.Common.Server
 			if (spawnPoint == 0)
 				return true;
 
-			var existingClient = server.LobbyInfo.Clients.Find(cc => cc.SpawnPoint == spawnPoint);
+			var existingClient = server.LobbyInfo.Clients.FirstOrDefault(cc => cc.SpawnPoint == spawnPoint);
 			if (client != existingClient && !client.IsAdmin)
 			{
 				server.SendLocalizedMessageTo(conn, AdminClearSpawn);
diff --git a/OpenRA.Mods.Common/ServerTraits/SkirmishLogic.cs b/OpenRA.Mods.Common/ServerTraits/SkirmishLogic.cs
index e3585733d3..537ef429bd 100644
--- a/OpenRA.Mods.Common/ServerTraits/SkirmishLogic.cs
+++ b/OpenRA.Mods.Common/ServerTraits/SkirmishLogic.cs
@@ -165,7 +165,7 @@ namespace OpenRA.Mods.Common.Server
 
 			var slot = server.LobbyInfo.FirstEmptyBotSlot();
 			var bot = server.Map.PlayerActorInfo.TraitInfos<IBotInfo>().Select(t => t.Type).FirstOrDefault();
-			var botController = server.LobbyInfo.Clients.Find(c => c.IsAdmin);
+			var botController = server.LobbyInfo.Clients.FirstOrDefault(c => c.IsAdmin);
 			if (slot != null && bot != null)
 				server.InterpretCommand($"slot_bot {slot} {botController.Index} {bot}", conn);
 		}
diff --git a/OpenRA.Mods.Common/Traits/AttackMove.cs b/OpenRA.Mods.Common/Traits/AttackMove.cs
index 71b32cab3c..8088170e99 100644
--- a/OpenRA.Mods.Common/Traits/AttackMove.cs
+++ b/OpenRA.Mods.Common/Traits/AttackMove.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -163,7 +162,7 @@ namespace OpenRA.Mods.Common.Traits
 				if (world.Map.Contains(cell))
 				{
 					var explored = subject.Actor.Owner.Shroud.IsExplored(cell);
-					var cannotMove = Array.Find(subjects, a => !a.Trait.Info.MoveIntoShroud).Trait;
+					var cannotMove = subjects.FirstOrDefault(a => !a.Trait.Info.MoveIntoShroud).Trait;
 					var blocked = !explored && cannotMove != null;
 
 					if (isAssaultMove)
diff --git a/OpenRA.Mods.Common/Traits/BotModules/SquadManagerBotModule.cs b/OpenRA.Mods.Common/Traits/BotModules/SquadManagerBotModule.cs
index 61c345aa31..56e35ba288 100644
--- a/OpenRA.Mods.Common/Traits/BotModules/SquadManagerBotModule.cs
+++ b/OpenRA.Mods.Common/Traits/BotModules/SquadManagerBotModule.cs
@@ -305,7 +305,7 @@ namespace OpenRA.Mods.Common.Traits
 		// HACK: Use of this function requires that there is one squad of this type.
 		Squad GetSquadOfType(SquadType type)
 		{
-			return Squads.Find(s => s.Type == type);
+			return Squads.FirstOrDefault(s => s.Type == type);
 		}
 
 		Squad RegisterNewSquad(IBot bot, SquadType type, (Actor Actor, WVec Offset) target = default)
diff --git a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs
index 6cbdb63e09..7d4333c418 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -143,7 +142,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 
 			var currentTransform = self.CurrentActivity as Transform;
-			var transform = Array.Find(transforms, t => !t.IsTraitDisabled && !t.IsTraitPaused);
+			var transform = transforms.FirstOrDefault(t => !t.IsTraitDisabled && !t.IsTraitPaused);
 			if (transform == null && currentTransform == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs
index adc208f88b..19f0196833 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -95,7 +94,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 
 			var currentTransform = self.CurrentActivity as Transform;
-			var transform = Array.Find(transforms, t => !t.IsTraitDisabled && !t.IsTraitPaused);
+			var transform = transforms.FirstOrDefault(t => !t.IsTraitDisabled && !t.IsTraitPaused);
 			if (transform == null && currentTransform == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs
index dddff6fc8e..d04046245d 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -121,7 +120,7 @@ namespace OpenRA.Mods.Common.Traits
 					return;
 
 				var currentTransform = self.CurrentActivity as Transform;
-				var transform = Array.Find(transforms, t => !t.IsTraitDisabled && !t.IsTraitPaused);
+				var transform = transforms.FirstOrDefault(t => !t.IsTraitDisabled && !t.IsTraitPaused);
 				if (transform == null && currentTransform == null)
 					return;
 
diff --git a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs
index bc82e4e9bb..568e394492 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -129,7 +128,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 
 			var currentTransform = self.CurrentActivity as Transform;
-			var transform = Array.Find(transforms, t => !t.IsTraitDisabled && !t.IsTraitPaused);
+			var transform = transforms.FirstOrDefault(t => !t.IsTraitDisabled && !t.IsTraitPaused);
 			if (transform == null && currentTransform == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs
index b6c85cbcf2..e569dce002 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Activities;
@@ -123,7 +122,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 
 			var currentTransform = self.CurrentActivity as Transform;
-			var transform = Array.Find(transforms, t => !t.IsTraitDisabled && !t.IsTraitPaused);
+			var transform = transforms.FirstOrDefault(t => !t.IsTraitDisabled && !t.IsTraitPaused);
 			if (transform == null && currentTransform == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Crates/GrantExternalConditionCrateAction.cs b/OpenRA.Mods.Common/Traits/Crates/GrantExternalConditionCrateAction.cs
index 53f7c72bcf..7997e642e2 100644
--- a/OpenRA.Mods.Common/Traits/Crates/GrantExternalConditionCrateAction.cs
+++ b/OpenRA.Mods.Common/Traits/Crates/GrantExternalConditionCrateAction.cs
@@ -84,7 +84,7 @@ namespace OpenRA.Mods.Common.Traits
 			{
 				if (external == null || !external.CanGrantCondition(self))
 				{
-					external = externals.Find(t => t.CanGrantCondition(self));
+					external = externals.FirstOrDefault(t => t.CanGrantCondition(self));
 					if (external == null)
 						break;
 				}
diff --git a/OpenRA.Mods.Common/Traits/Minelayer.cs b/OpenRA.Mods.Common/Traits/Minelayer.cs
index 0f7d24b60d..36c65746d7 100644
--- a/OpenRA.Mods.Common/Traits/Minelayer.cs
+++ b/OpenRA.Mods.Common/Traits/Minelayer.cs
@@ -310,7 +310,7 @@ namespace OpenRA.Mods.Common.Traits
 			protected override IEnumerable<IRenderable> Render(WorldRenderer wr, World world) { yield break; }
 			protected override IEnumerable<IRenderable> RenderAboveShroud(WorldRenderer wr, World world)
 			{
-				var minelayer = minelayers.Find(m => m.IsInWorld && !m.IsDead);
+				var minelayer = minelayers.FirstOrDefault(m => m.IsInWorld && !m.IsDead);
 				if (minelayer == null)
 					yield break;
 
diff --git a/OpenRA.Mods.Common/Traits/Player/ClassicParallelProductionQueue.cs b/OpenRA.Mods.Common/Traits/Player/ClassicParallelProductionQueue.cs
index a79046b279..38f4f31b7f 100644
--- a/OpenRA.Mods.Common/Traits/Player/ClassicParallelProductionQueue.cs
+++ b/OpenRA.Mods.Common/Traits/Player/ClassicParallelProductionQueue.cs
@@ -84,7 +84,7 @@ namespace OpenRA.Mods.Common.Traits
 			if (allProductionPaused)
 				return;
 
-			var item = Queue.Find(i => !i.Paused);
+			var item = Queue.FirstOrDefault(i => !i.Paused);
 			if (item == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Player/GameSaveViewportManager.cs b/OpenRA.Mods.Common/Traits/Player/GameSaveViewportManager.cs
index 880cb76b0b..16bacdbd46 100644
--- a/OpenRA.Mods.Common/Traits/Player/GameSaveViewportManager.cs
+++ b/OpenRA.Mods.Common/Traits/Player/GameSaveViewportManager.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using OpenRA.Graphics;
 using OpenRA.Traits;
@@ -34,7 +33,7 @@ namespace OpenRA.Mods.Common.Traits
 			// TODO: This won't make sense for MP saves
 			var localPlayer = worldRenderer.World.LocalPlayer;
 			if ((localPlayer != null && localPlayer.PlayerActor != self) ||
-				(localPlayer == null && self.Owner != Array.Find(self.World.Players, p => p.IsBot)))
+				(localPlayer == null && self.Owner != self.World.Players.FirstOrDefault(p => p.IsBot)))
 				return null;
 
 			var nodes = new List<MiniYamlNode>()
diff --git a/OpenRA.Mods.Common/Traits/Player/ParallelProductionQueue.cs b/OpenRA.Mods.Common/Traits/Player/ParallelProductionQueue.cs
index d9e74d770f..6a1dfca704 100644
--- a/OpenRA.Mods.Common/Traits/Player/ParallelProductionQueue.cs
+++ b/OpenRA.Mods.Common/Traits/Player/ParallelProductionQueue.cs
@@ -27,7 +27,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			CancelUnbuildableItems();
 
-			var item = Queue.Find(i => !i.Paused);
+			var item = Queue.FirstOrDefault(i => !i.Paused);
 			if (item == null)
 				return;
 
diff --git a/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs b/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs
index fd6b6fb08c..949d1c8c67 100644
--- a/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs
+++ b/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs
@@ -175,7 +175,7 @@ namespace OpenRA.Mods.Common.Traits
 							.Where(p => p.AcceptsPlug(plugInfo.Type))
 							.ToList();
 
-						var pluggable = pluggables.Find(p => a.Location + p.Info.Offset == targetLocation)
+						var pluggable = pluggables.FirstOrDefault(p => a.Location + p.Info.Offset == targetLocation)
 							?? pluggables.FirstOrDefault();
 
 						if (pluggable == null)
diff --git a/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs b/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs
index 0de33915a9..4466b31e6e 100644
--- a/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs
+++ b/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs
@@ -515,7 +515,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		protected virtual void PauseProduction(string itemName, bool paused)
 		{
-			Queue.Find(a => a.Item == itemName)?.Pause(paused);
+			Queue.FirstOrDefault(a => a.Item == itemName)?.Pause(paused);
 		}
 
 		protected virtual void CancelProduction(string itemName, uint numberToCancel)
diff --git a/OpenRA.Mods.Common/Traits/SupportPowers/SelectDirectionalTarget.cs b/OpenRA.Mods.Common/Traits/SupportPowers/SelectDirectionalTarget.cs
index 81667a72b8..d68f8881dd 100644
--- a/OpenRA.Mods.Common/Traits/SupportPowers/SelectDirectionalTarget.cs
+++ b/OpenRA.Mods.Common/Traits/SupportPowers/SelectDirectionalTarget.cs
@@ -151,7 +151,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		Arrow GetArrow(double degree)
 		{
-			var arrow = Array.Find(directionArrows, d => d.EndAngle >= degree);
+			var arrow = directionArrows.FirstOrDefault(d => d.EndAngle >= degree);
 			return arrow ?? directionArrows[0];
 		}
 
diff --git a/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs b/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs
index f6996e7bba..15fd3c0fc1 100644
--- a/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs
+++ b/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs
@@ -222,7 +222,7 @@ namespace OpenRA.Mods.Common.Traits
 			if (!Ready)
 				return;
 
-			var power = Instances.Find(i => !i.IsTraitPaused);
+			var power = Instances.FirstOrDefault(i => !i.IsTraitPaused);
 
 			if (power == null)
 				return;
diff --git a/OpenRA.Mods.Common/Traits/World/EditorActorLayer.cs b/OpenRA.Mods.Common/Traits/World/EditorActorLayer.cs
index ff83a0c110..e1acae47be 100644
--- a/OpenRA.Mods.Common/Traits/World/EditorActorLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/EditorActorLayer.cs
@@ -332,7 +332,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public EditorActorPreview this[string id]
 		{
-			get { return previews.Find(p => p.ID.Equals(id, StringComparison.OrdinalIgnoreCase)); }
+			get { return previews.FirstOrDefault(p => p.ID.Equals(id, StringComparison.OrdinalIgnoreCase)); }
 		}
 	}
 }
diff --git a/OpenRA.Mods.Common/UpdateRules/Rules/20231010/AbstractDocking.cs b/OpenRA.Mods.Common/UpdateRules/Rules/20231010/AbstractDocking.cs
index d105535094..9b69258ce3 100644
--- a/OpenRA.Mods.Common/UpdateRules/Rules/20231010/AbstractDocking.cs
+++ b/OpenRA.Mods.Common/UpdateRules/Rules/20231010/AbstractDocking.cs
@@ -102,7 +102,7 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 					refineryNode.RemoveNode(dockOffsetNode);
 				}
 
-				var buildingNode = actorNode.Value.Nodes.Find(n => buildings.Any(b => n.KeyMatches(b, includeRemovals: false)));
+				var buildingNode = actorNode.Value.Nodes.FirstOrDefault(n => buildings.Any(b => n.KeyMatches(b, includeRemovals: false)));
 				if (buildingNode != null)
 				{
 					var dimensions = buildingNode.ChildrenMatching("Dimensions", includeRemovals: false).FirstOrDefault()?.NodeValue<CVec>() ?? new CVec(1, 1);
diff --git a/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs b/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
index 0a7283ded3..f667d8a5a7 100644
--- a/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
+++ b/OpenRA.Mods.Common/UpdateRules/UpdatePath.cs
@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.UpdateRules.Rules;
@@ -99,7 +98,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 			if (namedType != null && namedType.IsSubclassOf(typeof(UpdateRule)))
 				return new[] { (UpdateRule)objectCreator.CreateBasic(namedType) };
 
-			return Array.Find(Paths, p => p.source == source)?.Rules(chain);
+			return Paths.FirstOrDefault(p => p.source == source)?.Rules(chain);
 		}
 
 		public static IEnumerable<string> KnownPaths { get { return Paths.Select(p => p.source); } }
diff --git a/OpenRA.Mods.Common/UtilityCommands/Utilities.cs b/OpenRA.Mods.Common/UtilityCommands/Utilities.cs
index 95f36d1ebc..48e61433c3 100644
--- a/OpenRA.Mods.Common/UtilityCommands/Utilities.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/Utilities.cs
@@ -46,7 +46,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 			var fs = map ?? modData.DefaultFileSystem;
 			var topLevelNodes = MiniYaml.Load(fs, manifestNodes, mapProperty);
-			return topLevelNodes.Find(n => n.Key == key);
+			return topLevelNodes.FirstOrDefault(n => n.Key == key);
 		}
 	}
 }
diff --git a/OpenRA.Mods.Common/Widgets/ButtonWidget.cs b/OpenRA.Mods.Common/Widgets/ButtonWidget.cs
index 43724700ce..eeeb2a8069 100644
--- a/OpenRA.Mods.Common/Widgets/ButtonWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/ButtonWidget.cs
@@ -247,8 +247,7 @@ namespace OpenRA.Mods.Common.Widgets
 
 			var position = GetTextPosition(text, font, rb);
 
-			// PERF: Avoid LINQ by using Children.Find(...) != null instead of Children.Any(...)
-			var hover = Ui.MouseOverWidget == this || Children.Find(c => c == Ui.MouseOverWidget) != null;
+			var hover = Ui.MouseOverWidget == this || Children.FirstOrDefault(c => c == Ui.MouseOverWidget) != null;
 			DrawBackground(rb, disabled, Depressed, hover, highlighted);
 			if (Contrast)
 				font.DrawTextWithContrast(text, position + stateOffset,
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Editor/SaveMapLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Editor/SaveMapLogic.cs
index e0be9dc4e0..768b3cb983 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Editor/SaveMapLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Editor/SaveMapLogic.cs
@@ -146,8 +146,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 				if (map.Package != null)
 				{
-					selectedDirectory = writableDirectories.Find(k => k.Folder.Contains(map.Package.Name));
-					selectedDirectory ??= writableDirectories.Find(k => Directory.GetDirectories(k.Folder.Name).Any(f => f.Contains(map.Package.Name)));
+					selectedDirectory = writableDirectories.FirstOrDefault(k => k.Folder.Contains(map.Package.Name));
+					selectedDirectory ??= writableDirectories.FirstOrDefault(k => Directory.GetDirectories(k.Folder.Name).Any(f => f.Contains(map.Package.Name)));
 				}
 
 				// Prioritize MapClassification.User directories over system directories
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/ClassicProductionLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/ClassicProductionLogic.cs
index 64ce412f79..b09ce9ded8 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/ClassicProductionLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/ClassicProductionLogic.cs
@@ -33,7 +33,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 			void SelectTab(bool reverse)
 			{
-				palette.CurrentQueue = Array.Find(queues, q => q.Enabled);
+				palette.CurrentQueue = queues.FirstOrDefault(q => q.Enabled);
 
 				// When a tab is selected, scroll to the top because the current row position may be invalid for the new tab
 				palette.ScrollToTop();
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameInfoStatsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameInfoStatsLogic.cs
index 17519f3ac3..8131d86b87 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameInfoStatsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameInfoStatsLogic.cs
@@ -212,7 +212,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			}
 
 			var localClient = orderManager.LocalClient;
-			var localPlayer = localClient == null ? null : Array.Find(world.Players, player => player.ClientIndex == localClient.Index);
+			var localPlayer = localClient == null ? null : world.Players.FirstOrDefault(player => player.ClientIndex == localClient.Index);
 			bool LocalPlayerCanKick() => localClient != null
 				&& (Game.IsHost || ((!orderManager.LocalClient.IsObserver) && localPlayer.WinState == WinState.Undefined));
 			bool CanClientBeKicked(Session.Client client, Func<bool> isVoteKick) =>
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentPromptLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentPromptLogic.cs
index 41cc86066b..9fcdbebcca 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentPromptLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentPromptLogic.cs
@@ -80,7 +80,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				var downloadYaml = MiniYaml.Load(modFileSystem, content.Downloads, null);
 				modFileSystem.UnmountAll();
 
-				var download = downloadYaml.Find(n => n.Key == content.QuickDownload);
+				var download = downloadYaml.FirstOrDefault(n => n.Key == content.QuickDownload);
 				if (download == null)
 					throw new InvalidOperationException($"Mod QuickDownload `{content.QuickDownload}` definition not found.");
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
index b3582d65ac..ace279b627 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
@@ -274,7 +274,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					var botTypes = map.PlayerActorInfo.TraitInfos<IBotInfo>().Select(t => t.Type);
 					var options = new Dictionary<string, IEnumerable<DropDownOption>>();
 
-					var botController = orderManager.LobbyInfo.Clients.Find(c => c.IsAdmin);
+					var botController = orderManager.LobbyInfo.Clients.FirstOrDefault(c => c.IsAdmin);
 					if (orderManager.LobbyInfo.Slots.Values.Any(s => s.AllowBots))
 					{
 						var botOptions = new List<DropDownOption>()
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs
index 05ce5ada7f..a9e0da0f9b 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyUtils.cs
@@ -74,7 +74,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			{
 				foreach (var b in map.PlayerActorInfo.TraitInfos<IBotInfo>())
 				{
-					var botController = orderManager.LobbyInfo.Clients.Find(c => c.IsAdmin);
+					var botController = orderManager.LobbyInfo.Clients.FirstOrDefault(c => c.IsAdmin);
 					bots.Add(new SlotDropDownOption(b.Name,
 						$"slot_bot {slot.PlayerReference} {botController.Index} {b.Type}",
 						() => client != null && client.Bot == b.Type));
@@ -266,7 +266,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 		static void ClearPlayerSpawnPoint(OrderManager orderManager, MapPreviewWidget mapPreview, MapPreview preview, MouseInput mi)
 		{
 			var selectedSpawn = DetermineSelectedSpawnPoint(mapPreview, preview, mi);
-			if (Game.IsHost || orderManager.LobbyInfo.Clients.Find(cc => cc.SpawnPoint == selectedSpawn) == orderManager.LocalClient)
+			if (Game.IsHost || orderManager.LobbyInfo.Clients.FirstOrDefault(cc => cc.SpawnPoint == selectedSpawn) == orderManager.LocalClient)
 				orderManager.IssueOrder(Order.Command($"clear_spawn {selectedSpawn}"));
 		}
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
index 42bc19ef22..2b68c50ab7 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
@@ -356,7 +356,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 				gameModeDropdown.GetText = () =>
 				{
-					var item = categories.Find(m => m.Category == category);
+					var item = categories.FirstOrDefault(m => m.Category == category);
 					if (item == default((string, int)))
 						item.Category = TranslationProvider.GetString(NoMatches);
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
index 3923e4542f..b6926cbdf3 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
@@ -696,7 +696,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 		void SelectFirstVisibleReplay()
 		{
-			SelectReplay(replays.Find(r => replayState[r].Visible));
+			SelectReplay(replays.FirstOrDefault(r => replayState[r].Visible));
 		}
 
 		void SelectReplay(ReplayMetadata replay)
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
index e1e691e0b3..f2bf3d3550 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
@@ -103,7 +103,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			videoVolumeSlider.OnChange += x => Game.Sound.VideoVolume = x;
 
 			var devices = Game.Sound.AvailableDevices();
-			soundDevice = Array.Find(devices, d => d.Device == ss.Device) ?? devices[0];
+			soundDevice = devices.FirstOrDefault(d => d.Device == ss.Device) ?? devices[0];
 
 			var audioDeviceDropdown = panel.Get<DropDownButtonWidget>("AUDIO_DEVICE");
 			audioDeviceDropdown.OnMouseDown = _ => ShowAudioDeviceDropdown(audioDeviceDropdown, devices, scrollPanel);
diff --git a/OpenRA.Mods.Common/Widgets/ResourcePreviewWidget.cs b/OpenRA.Mods.Common/Widgets/ResourcePreviewWidget.cs
index 1f34d7f8f2..5a36e78c06 100644
--- a/OpenRA.Mods.Common/Widgets/ResourcePreviewWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/ResourcePreviewWidget.cs
@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Common.Widgets
 			{
 				resourceType = value;
 				if (resourceType != null)
-					resourceRenderer = Array.Find(resourceRenderers, r => r.ResourceTypes.Contains(resourceType));
+					resourceRenderer = resourceRenderers.FirstOrDefault(r => r.ResourceTypes.Contains(resourceType));
 				else
 					resourceRenderer = null;
 			}
diff --git a/OpenRA.Mods.Common/Widgets/ScrollPanelWidget.cs b/OpenRA.Mods.Common/Widgets/ScrollPanelWidget.cs
index 74e0eb4a4a..92faef6849 100644
--- a/OpenRA.Mods.Common/Widgets/ScrollPanelWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/ScrollPanelWidget.cs
@@ -283,7 +283,7 @@ namespace OpenRA.Mods.Common.Widgets
 
 		public void ScrollToItem(string itemKey, bool smooth = false)
 		{
-			var item = Children.Find(c => c is ScrollItemWidget si && si.ItemKey == itemKey);
+			var item = Children.FirstOrDefault(c => c is ScrollItemWidget si && si.ItemKey == itemKey);
 
 			if (item != null)
 				ScrollToItem(item, smooth);
@@ -291,7 +291,7 @@ namespace OpenRA.Mods.Common.Widgets
 
 		public void ScrollToSelectedItem()
 		{
-			var item = Children.Find(c => c is ScrollItemWidget si && si.IsSelected());
+			var item = Children.FirstOrDefault(c => c is ScrollItemWidget si && si.IsSelected());
 
 			if (item != null)
 				ScrollToItem(item);
@@ -468,7 +468,7 @@ namespace OpenRA.Mods.Common.Widgets
 				if (collection != col)
 					return;
 
-				var widget = Children.Find(w => widgetItemEquals(w, item));
+				var widget = Children.FirstOrDefault(w => widgetItemEquals(w, item));
 				if (widget != null)
 					RemoveChild(widget);
 			});
diff --git a/OpenRA.Mods.D2k/UtilityCommands/D2kMapImporter.cs b/OpenRA.Mods.D2k/UtilityCommands/D2kMapImporter.cs
index 0eabbd17fa..f3c43a6abd 100644
--- a/OpenRA.Mods.D2k/UtilityCommands/D2kMapImporter.cs
+++ b/OpenRA.Mods.D2k/UtilityCommands/D2kMapImporter.cs
@@ -505,7 +505,7 @@ namespace OpenRA.Mods.D2k.UtilityCommands
 			}
 
 			// Get the first tileset template that contains the Frame ID of the original map's tile with the requested index
-			var template = tileSetsFromYaml.Find(x => ((DefaultTerrainTemplateInfo)x).Frames.Contains(tileIndex));
+			var template = tileSetsFromYaml.FirstOrDefault(x => ((DefaultTerrainTemplateInfo)x).Frames.Contains(tileIndex));
 
 			// HACK: The arrakis.yaml tileset file seems to be missing some tiles, so just get a replacement for them
 			// Also used for duplicate tiles that are taken from only tileset
@@ -525,7 +525,7 @@ namespace OpenRA.Mods.D2k.UtilityCommands
 			}
 
 			var templateIndex = template.Id;
-			var frameIndex = Array.IndexOf(((DefaultTerrainTemplateInfo)template).Frames, tileIndex);
+			var frameIndex = ((DefaultTerrainTemplateInfo)template).Frames.IndexOf(tileIndex);
 
 			return new TerrainTile(templateIndex, (byte)((frameIndex == -1) ? 0 : frameIndex));
 		}
diff --git a/OpenRA.Platforms.Default/Sdl2Input.cs b/OpenRA.Platforms.Default/Sdl2Input.cs
index 19cb6c53e0..0edbea1852 100644
--- a/OpenRA.Platforms.Default/Sdl2Input.cs
+++ b/OpenRA.Platforms.Default/Sdl2Input.cs
@@ -208,7 +208,7 @@ namespace OpenRA.Platforms.Default
 					{
 						var rawBytes = new byte[SDL.SDL_TEXTINPUTEVENT_TEXT_SIZE];
 						unsafe { Marshal.Copy((IntPtr)e.text.text, rawBytes, 0, SDL.SDL_TEXTINPUTEVENT_TEXT_SIZE); }
-						inputHandler.OnTextInput(Encoding.UTF8.GetString(rawBytes, 0, Array.IndexOf(rawBytes, (byte)0)));
+						inputHandler.OnTextInput(Encoding.UTF8.GetString(rawBytes, 0, rawBytes.IndexOf((byte)0)));
 						break;
 					}