diff --git a/OpenRA.Game/GameRules/Warhead.cs b/OpenRA.Game/GameRules/Warhead.cs
index 043e5772e6..8928e9f9b1 100644
--- a/OpenRA.Game/GameRules/Warhead.cs
+++ b/OpenRA.Game/GameRules/Warhead.cs
@@ -23,12 +23,20 @@ namespace OpenRA.GameRules
 
 		[Desc("What types of targets are unaffected.", "Overrules ValidTargets.")]
 		public readonly string[] InvalidTargets = { };
+		
+		[Desc("What diplomatic stances are affected.")]
+		public readonly Stance ValidStances = Stance.Ally | Stance.Neutral | Stance.Enemy;
+		
+		[Desc("Can this warhead affect the actor that fired it.")]
+		public readonly bool AffectsParent = true;
 
 		[Desc("Delay in ticks before applying the warhead effect.","0 = instant (old model).")]
 		public readonly int Delay = 0;
 
+		///<summary>Applies the warhead's effect against the target.</summary>
 		public abstract void DoImpact(Target target, Actor firedBy, IEnumerable<int> damageModifiers);
 
+		///<summary>Checks if the warhead is valid against (can do something to) the target.</summary>
 		public bool IsValidAgainst(Target target, World world, Actor firedBy)
 		{
 			if (target.Type == TargetType.Actor)
@@ -58,53 +66,46 @@ namespace OpenRA.GameRules
 		// assumption has been removed from the yaml definitions
 		public virtual bool CanTargetActor(ActorInfo victim, Actor firedBy) { return false; }
 
+		///<summary>Checks if the warhead is valid against (can do something to) the actor.</summary>
 		public bool IsValidAgainst(Actor victim, Actor firedBy)
 		{
 			if (!CanTargetActor(victim.Info, firedBy))
 				return false;
 
+			if (!AffectsParent && victim == firedBy)
+				return false;
+
+			var stance = firedBy.Owner.Stances[victim.Owner];
+			if (!ValidStances.HasFlag(stance))
+				return false;
+
 			// A target type is valid if it is in the valid targets list, and not in the invalid targets list.
-			return InTargetList(victim, firedBy, ValidTargets) &&
-				!InTargetList(victim, firedBy, InvalidTargets);
-		}
-
-		public static bool InTargetList(Actor victim, Actor firedBy, string[] targetList)
-		{
-			if (!targetList.Any())
-				return false;
-
 			var targetable = victim.TraitOrDefault<ITargetable>();
-			if (targetable == null)
-				return false;
-			if (!targetList.Intersect(targetable.TargetTypes).Any())
+			if (targetable == null || !ValidTargets.Intersect(targetable.TargetTypes).Any()
+				|| InvalidTargets.Intersect(targetable.TargetTypes).Any())
 				return false;
 
 			return true;
 		}
 
+		///<summary>Checks if the warhead is valid against (can do something to) the frozen actor.</summary>
 		public bool IsValidAgainst(FrozenActor victim, Actor firedBy)
 		{
 			if (!CanTargetActor(victim.Info, firedBy))
 				return false;
 
+			// AffectsParent checks do not make sense for FrozenActors, so skip to stance checks
+			var stance = firedBy.Owner.Stances[victim.Owner];
+			if (!ValidStances.HasFlag(stance))
+				return false;
+
 			// A target type is valid if it is in the valid targets list, and not in the invalid targets list.
-			return InTargetList(victim, firedBy, ValidTargets) &&
-				!InTargetList(victim, firedBy, InvalidTargets);
-		}
-
-		public static bool InTargetList(FrozenActor victim, Actor firedBy, string[] targetList)
-		{
-			// Frozen Actors need to be handled slightly differently. Since FrozenActor.Actor can be null if the Actor is dead.
-			if (!targetList.Any())
-				return false;
-
 			var targetable = victim.Info.Traits.GetOrDefault<ITargetableInfo>();
-			if (targetable == null)
+			if (targetable == null || !ValidTargets.Intersect(targetable.GetTargetTypes()).Any()
+				|| InvalidTargets.Intersect(targetable.GetTargetTypes()).Any())
 				return false;
-			if (!targetList.Intersect(targetable.GetTargetTypes()).Any())
-				return false;
-			
+
 			return true;
 		}
-   }
+	}
 }
diff --git a/OpenRA.Game/GameRules/WeaponInfo.cs b/OpenRA.Game/GameRules/WeaponInfo.cs
index 6a40d3186b..567d0602c9 100644
--- a/OpenRA.Game/GameRules/WeaponInfo.cs
+++ b/OpenRA.Game/GameRules/WeaponInfo.cs
@@ -92,6 +92,7 @@ namespace OpenRA.GameRules
 			return retList;
 		}
 
+		///<summary>Checks if the weapon is valid against (can target) the target.</summary>
 		public bool IsValidAgainst(Target target, World world, Actor firedBy)
 		{
 			if (target.Type == TargetType.Actor)
@@ -117,30 +118,31 @@ namespace OpenRA.GameRules
 			return false;
 		}
 
+		///<summary>Checks if the weapon is valid against (can target) the actor.</summary>
 		public bool IsValidAgainst(Actor victim, Actor firedBy)
 		{
-			if (!Warheads.Any(w => w.IsValidAgainst(victim, firedBy)))
-				return false;
-
 			var targetable = victim.TraitOrDefault<ITargetable>();
 			if (targetable == null || !ValidTargets.Intersect(targetable.TargetTypes).Any()
 				|| InvalidTargets.Intersect(targetable.TargetTypes).Any())
 				return false;
 
-			return true;
-		}
-
-		public bool IsValidAgainst(FrozenActor victim, Actor firedBy)
-		{
-			// Frozen Actors are treated slightly differently.
 			if (!Warheads.Any(w => w.IsValidAgainst(victim, firedBy)))
 				return false;
 
+			return true;
+		}
+
+		///<summary>Checks if the weapon is valid against (can target) the frozen actor.</summary>
+		public bool IsValidAgainst(FrozenActor victim, Actor firedBy)
+		{
 			var targetable = victim.Info.Traits.GetOrDefault<ITargetableInfo>();
 			if (targetable == null || !ValidTargets.Intersect(targetable.GetTargetTypes()).Any()
 				|| InvalidTargets.Intersect(targetable.GetTargetTypes()).Any())
 				return false;
 
+			if (!Warheads.Any(w => w.IsValidAgainst(victim, firedBy)))
+				return false;
+
 			return true;
 		}
 
diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index 1fa0b983f5..9eb5b166f8 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -22,7 +22,14 @@ namespace OpenRA.Traits
 	// depends on the order of pips in WorldRenderer.cs!
 	public enum PipType { Transparent, Green, Yellow, Red, Gray, Blue, Ammo, AmmoEmpty };
 	public enum TagType { None, Fake, Primary };
-	public enum Stance { Enemy, Neutral, Ally };
+	
+	[Flags]
+	public enum Stance
+	{
+		Enemy = 1,
+		Neutral = 2,
+		Ally = 4,
+	}
 
 	[Flags]
 	public enum ImpactType
diff --git a/OpenRA.Utility/UpgradeRules.cs b/OpenRA.Utility/UpgradeRules.cs
index ce95f9edab..38035f6eab 100644
--- a/OpenRA.Utility/UpgradeRules.cs
+++ b/OpenRA.Utility/UpgradeRules.cs
@@ -574,7 +574,7 @@ namespace OpenRA.Utility
 										newYaml.Add(new MiniYamlNode("Size", newValue));
 									}
 
-									var keywords = new List<string>{ "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
+									var keywords = new List<string> { "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
 
 									foreach(var keyword in keywords)
 									{
@@ -610,7 +610,7 @@ namespace OpenRA.Utility
 										newYaml.Add(new MiniYamlNode("Spread", newValue));
 									}
 
-									var keywords = new List<string>{ "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
+									var keywords = new List<string> { "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
 
 									foreach(var keyword in keywords)
 									{
@@ -637,7 +637,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "Spread", "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
+									var keywords = new List<string> { "Spread", "Damage", "InfDeath", "PreventProne", "ProneModifier", "Delay" };
 
 									foreach(var keyword in keywords)
 									{
@@ -666,7 +666,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "Size", "Delay", "ValidTargets", "InvalidTargets" };
+									var keywords = new List<string> { "Size", "Delay", "ValidTargets", "InvalidTargets" };
 									foreach(var keyword in keywords)
 									{
 										var temp = curNode.Value.Nodes.FirstOrDefault(n => n.Key == keyword);
@@ -684,7 +684,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "AddsResourceType", "Size", "Delay", "ValidTargets", "InvalidTargets" };
+									var keywords = new List<string> { "AddsResourceType", "Size", "Delay", "ValidTargets", "InvalidTargets" };
 
 									foreach(var keyword in keywords)
 									{
@@ -703,7 +703,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "SmudgeType", "Size", "Delay", "ValidTargets", "InvalidTargets" };
+									var keywords = new List<string> { "SmudgeType", "Size", "Delay", "ValidTargets", "InvalidTargets" };
 
 									foreach(var keyword in keywords)
 									{
@@ -723,7 +723,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "Explosion", "ImpactSound", "Delay", "ValidTargets", "InvalidTargets", "ValidImpactTypes", "InvalidImpactTypes" };
+									var keywords = new List<string> { "Explosion", "ImpactSound", "Delay", "ValidTargets", "InvalidTargets", "ValidImpactTypes", "InvalidImpactTypes" };
 
 									foreach(var keyword in keywords)
 									{
@@ -744,7 +744,7 @@ namespace OpenRA.Utility
 
 									var newYaml = new List<MiniYamlNode>();
 
-									var keywords = new List<string>{ "WaterExplosion", "WaterImpactSound", "Delay", "ValidTargets", "InvalidTargets", "ValidImpactTypes", "InvalidImpactTypes" };
+									var keywords = new List<string> { "WaterExplosion", "WaterImpactSound", "Delay", "ValidTargets", "InvalidTargets", "ValidImpactTypes", "InvalidImpactTypes" };
 
 									foreach(var keyword in keywords)
 									{