Index: binaries/data/mods/public/simulation/components/PlayerManager.js
===================================================================
--- binaries/data/mods/public/simulation/components/PlayerManager.js
+++ binaries/data/mods/public/simulation/components/PlayerManager.js
@@ -25,6 +25,12 @@
 	newDiplo[id] = 1;
 	cmpPlayer.SetDiplomacy(newDiplo);
 
+	Engine.BroadcastMessage(MT_PlayerChanged, {
+		"player": id,
+		"from": -1,
+		"to": ent
+	});
+
 	return id;
 };
 
@@ -64,6 +70,12 @@
 		if (cmpOwnership)
 			cmpOwnership.SetOwner(id);
 	}
+
+	Engine.BroadcastMessage(MT_PlayerChanged, {
+		"player": id,
+		"from": oldent,
+		"to": ent
+	});
 };
 
 /**
@@ -126,8 +138,15 @@
 PlayerManager.prototype.RemoveAllPlayers = function()
 {
 	// Destroy existing player entities
-	for (var id of this.playerEntities)
-		Engine.DestroyEntity(id);
+	for (let player in this.playerEntities)
+	{
+		Engine.BroadcastMessage(MT_PlayerChanged, {
+			"player": player,
+			"from": this.playerEntities[player],
+			"to": -1
+		});
+		Engine.DestroyEntity(this.playerEntities[player]);
+	}
 
 	this.playerEntities = [];
 };
@@ -138,6 +157,11 @@
 		return;
 
 	var lastId = this.playerEntities.pop();
+	Engine.BroadcastMessage(MT_PlayerChanged, {
+		"player": this.playerEntities.length + 1,
+		"from": lastId,
+		"to": -1
+	});
 	Engine.DestroyEntity(lastId);
 };
 
Index: binaries/data/mods/public/simulation/components/interfaces/PlayerManager.js
===================================================================
--- /dev/null
+++ binaries/data/mods/public/simulation/components/interfaces/PlayerManager.js
@@ -0,0 +1,6 @@
+/**
+ * Message of the form { player": number, "from": number, "to": number }
+ * sent from PlayerManager component to warn other components when a player changed entities.
+ * This is also sent when the player gets created or destroyed.
+ */
+Engine.RegisterMessageType("PlayerChanged");