diff -r 4e4111a75256 -r f01798038c2e hedgewars/uScript.pas
--- a/hedgewars/uScript.pas	Fri Oct 05 16:49:17 2018 +0200
+++ b/hedgewars/uScript.pas	Fri Oct 05 17:27:12 2018 +0200
@@ -3970,6 +3970,12 @@
 // import some variables
 ScriptSetString(_S'LOCALE', cLocale);
 
+// Add aliases for amDuck and gtDuck because rubber duck was removed.
+// amDuck and gtDuck are deprecated and should be removed later.
+// TODO: Remove these aliases in a later version.
+ScriptSetInteger('amDuck', Ord(amCreeper));
+ScriptSetInteger('gtDuck', Ord(gtCreeper));
+
 // import game flags
 ScriptSetInteger('gfSwitchHog', gfSwitchHog);
 ScriptSetInteger('gfMultiWeapon', gfMultiWeapon);