diff --git a/OpenRA.Game/Primitives/ActorInfoDictionary.cs b/OpenRA.Game/Primitives/ActorInfoDictionary.cs
index a11d1c2584..74b8285079 100644
--- a/OpenRA.Game/Primitives/ActorInfoDictionary.cs
+++ b/OpenRA.Game/Primitives/ActorInfoDictionary.cs
@@ -24,6 +24,15 @@ namespace OpenRA
 			ArgumentNullException.ThrowIfNull(dict);
 
 			this.dict = new Dictionary<string, ActorInfo>(dict);
+
+			// Include an empty entry for each system actor to guarantee that
+			// they will be defined even if not specified in the mod yaml
+			foreach (var systemActor in Enum.GetValues<SystemActors>())
+			{
+				var key = systemActor.ToString().ToLowerInvariant();
+				if (!dict.ContainsKey(key))
+					this.dict[key] = new ActorInfo(key);
+			}
 		}
 
 		public bool ContainsKey(string key) => dict.ContainsKey(key);
diff --git a/mods/cnc-content/mod.yaml b/mods/cnc-content/mod.yaml
index 720d7eafec..b315d8b1c9 100644
--- a/mods/cnc-content/mod.yaml
+++ b/mods/cnc-content/mod.yaml
@@ -11,7 +11,6 @@ FileSystem: DefaultFileSystem
 		$cnc-content: cnccontent
 
 Rules:
-	content|rules.yaml
 
 Cursors:
 	content|cursors.yaml
diff --git a/mods/common-content/rules.yaml b/mods/common-content/rules.yaml
deleted file mode 100644
index f10c1b582f..0000000000
--- a/mods/common-content/rules.yaml
+++ /dev/null
@@ -1 +0,0 @@
-World:
diff --git a/mods/d2k-content/mod.yaml b/mods/d2k-content/mod.yaml
index c33aac5f5d..1d21728c35 100644
--- a/mods/d2k-content/mod.yaml
+++ b/mods/d2k-content/mod.yaml
@@ -11,7 +11,6 @@ FileSystem: DefaultFileSystem
 		$d2k-content: d2kcontent
 
 Rules:
-	content|rules.yaml
 
 Cursors:
 	content|cursors.yaml
diff --git a/mods/ra-content/mod.yaml b/mods/ra-content/mod.yaml
index 4059304d2f..aedd7add07 100644
--- a/mods/ra-content/mod.yaml
+++ b/mods/ra-content/mod.yaml
@@ -11,7 +11,6 @@ FileSystem: DefaultFileSystem
 		$ra-content: racontent
 
 Rules:
-	content|rules.yaml
 
 Cursors:
 	content|cursors.yaml
diff --git a/mods/ts-content/mod.yaml b/mods/ts-content/mod.yaml
index 607e542299..71a938be85 100644
--- a/mods/ts-content/mod.yaml
+++ b/mods/ts-content/mod.yaml
@@ -11,7 +11,6 @@ FileSystem: DefaultFileSystem
 		$ts-content: tscontent
 
 Rules:
-	content|rules.yaml
 
 Cursors:
 	content|cursors.yaml