Restored faulty left-click logic for now.

OpenRA.Game/Game.cs

@@ -27,6 +27,8 @@ namespace OpenRA
 {
 	public static class Game
 	{
+		public static MouseButtonPreference mouseButtonPreference = new MouseButtonPreference();
+
 		public const int NetTickScale = 3; // 120 ms net tick for 40 ms local tick
 		public const int Timestep = 40;
 		public const int TimestepJankThreshold = 250; // Don't catch up for delays larger than 250ms

OpenRA.Game/Input/InputHandler.cs

@@ -49,4 +49,25 @@ namespace OpenRA
 			Sync.CheckSyncUnchanged(world, () => Ui.HandleInput(input));
 		}
 	}
+
+	public class MouseButtonPreference
+	{
+
+		public MouseButton Action
+		{
+			get
+			{
+				return Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Left : MouseButton.Right;
+			}
+		}
+
+
+		public MouseButton Cancel
+		{
+			get
+			{
+				return Game.Settings.Game.UseClassicMouseStyle ? MouseButton.Right : MouseButton.Left;
+			}
+		}
+	}
 }

OpenRA.Game/Orders/UnitOrderGenerator.cs

@@ -96,7 +96,7 @@ namespace OpenRA.Orders
 			if (self.Destroyed || !target.IsValidFor(self))
 				return null;
 
-			if (mi.Button == MouseButton.Right)
+			if (mi.Button == Game.mouseButtonPreference.Action)
 			{
 				foreach (var o in self.TraitsImplementing<IIssueOrder>()
 					.SelectMany(trait => trait.Orders

OpenRA.Game/Settings.cs

@@ -130,6 +130,7 @@ namespace OpenRA
 		public float ViewportEdgeScrollStep = 10f;
 		public float UIScrollSpeed = 50f;
 
+		public bool UseClassicMouseStyle = false;
 		public bool AlwaysShowStatusBars = false;
 		public bool TeamHealthColors = false;
 

OpenRA.Game/Widgets/WorldInteractionControllerWidget.cs

@@ -55,6 +55,9 @@ namespace OpenRA.Widgets
 		public override bool HandleMouseInput(MouseInput mi)
 		{
 			var xy = worldRenderer.Viewport.ViewToWorldPx(mi.Location);
+
+			var useClassicMouseStyle = Game.Settings.Game.UseClassicMouseStyle;
+
 			var hasBox = SelectionBox != null;
 			var multiClick = mi.MultiTapCount >= 2;
 
@@ -66,7 +69,8 @@ namespace OpenRA.Widgets
 				dragStart = xy;
 
 				// place buildings
-				ApplyOrders(World, xy, mi);
+				if(!useClassicMouseStyle)
+					ApplyOrders(World, xy, mi);
 			}
 
 			if (mi.Button == MouseButton.Left && mi.Event == MouseInputEvent.Move && dragStart.HasValue)
@@ -74,6 +78,18 @@ namespace OpenRA.Widgets
 
 			if (mi.Button == MouseButton.Left && mi.Event == MouseInputEvent.Up)
 			{
+				if (useClassicMouseStyle && HasMouseFocus)
+				{
+					// order units around
+					if (!hasBox && World.Selection.Actors.Any() && !multiClick)
+					{
+						ApplyOrders(World, xy, mi);
+						YieldMouseFocus(mi);
+						return true;
+					}
+				}
+
+
 				if (World.OrderGenerator is UnitOrderGenerator)
 				{
 					if (multiClick)
@@ -97,9 +113,14 @@ namespace OpenRA.Widgets
 				YieldMouseFocus(mi);
 			}
 
-			// don't issue orders while selecting
-			if (mi.Button == MouseButton.Right && mi.Event == MouseInputEvent.Down && !hasBox)
-				ApplyOrders(World, xy, mi);
+			if (mi.Button == MouseButton.Right && mi.Event == MouseInputEvent.Down)
+			{
+				if (useClassicMouseStyle)
+					World.Selection.Clear();
+
+				if (!hasBox) // don't issue orders while selecting
+					ApplyOrders(World, xy, mi);
+			}
 
 			lastMousePosition = xy;
 
@@ -172,7 +193,7 @@ namespace OpenRA.Widgets
 				var mi = new MouseInput
 				{
 					Location = screenPos,
-					Button = MouseButton.Right,
+					Button = Game.mouseButtonPreference.Action,
 					Modifiers = Game.GetModifierKeys()
 				};