Index: binaries/data/mods/public/gui/lobby/lobby.js
===================================================================
--- binaries/data/mods/public/gui/lobby/lobby.js
+++ binaries/data/mods/public/gui/lobby/lobby.js
@@ -75,9 +75,28 @@
 var g_ChatCommandColor = "200 200 255";
 
 /**
- * All chat messages received since init (i.e. after lobby join and after returning from a game).
+ * All chat messages received since init (i.e. after lobby join and after returning from a game), spam count and spam timer.
  */
-var g_ChatMessages = [];
+var g_Chat = {
+	"messages": [],
+	"spamCount": 0,
+	"spamTimer": 0,
+	"spamHit": () => {
+		if (g_Chat.spamCount <= 3)
+			return false;
+
+		g_Chat.spamCount += 3;
+
+		addChatMessage({
+			"from": "system",
+			"text": sprintf(translate("Don't spam. Wait %(seconds)s seconds now."), {
+				"seconds": g_Chat.spamCount - 3
+			})
+		});
+		
+		return true;
+	}
+};
 
 /**
  * Rating of the current user.
@@ -1199,6 +1218,21 @@
 		updatePlayerList();
 }
 
+/*
+ * Spam filter counter reduce function per timeout.
+ */
+function chatSpamTimer()
+{
+	if (g_Chat.spamCount == 0)
+	{
+		g_Chat.spamTimer = 0;
+		return;
+	}
+
+	--g_Chat.spamCount;
+	 return setTimeout(chatSpamTimer, 1000);
+}
+
 /**
  * Executes a lobby command or sends GUI input directly as chat.
  */
@@ -1207,11 +1241,15 @@
 	let input = Engine.GetGUIObjectByName("chatInput");
 	let text = input.caption;
 
-	if (!text.length)
+	if (!text.length || g_Chat.spamHit())
 		return;
 
 	if (handleChatCommand(text))
+	{
 		Engine.LobbySendMessage(text);
+		++g_Chat.spamCount;
+		g_Chat.spamTimer = g_Chat.spamTimer || chatSpamTimer();
+	}
 
 	input.caption = "";
 }
@@ -1283,8 +1321,8 @@
 	if (!formatted)
 		return;
 
-	g_ChatMessages.push(formatted);
-	Engine.GetGUIObjectByName("chatText").caption = g_ChatMessages.join("\n");
+	g_Chat.messages.push(formatted);
+	Engine.GetGUIObjectByName("chatText").caption = g_Chat.messages.join("\n");
 }
 
 /**