Index: src/map/script.c
===================================================================
--- src/map/script.c	(revision 17322)
+++ src/map/script.c	(working copy)
@@ -15156,21 +15156,50 @@
 	return 0;
 }
 
-/* Work In Progress [Lupus]
 BUILDIN_FUNC(addmonsterdrop)
 {
-	int class_,item_id,chance;
-	class_=script_getnum(st,2);
+	struct mob_db *mob;
+	int item_id,rate,i,c = 0;
+
+	mob = mob_db(script_getnum(st,2));
+
 	item_id=script_getnum(st,3);
-	chance=script_getnum(st,4);
-	if(class_>1000 && item_id>500 && chance>0) {
-		script_pushint(st,1);
-	} else {
-		script_pushint(st,0);
+	rate=script_getnum(st,4);
+
+	if(!itemdb_exists(item_id)){
+		ShowError("addmonsterdrop: Nonexistant item %d requested.\n", item_id );
+		return 1;
 	}
+
+	if(mob) { //We got a valid monster, check for available drop slot
+		for(i = 0; i < MAX_MOB_DROP; i++) {
+			if(mob->dropitem[i].nameid) { 
+				if(mob->dropitem[i].nameid == item_id) { //If it equals item_id we update that drop
+					c = i;
+					break;
+				}
+				continue;
+			}
+			c = i;
+		}
+		if(c) { //Fill in the slot with the item and rate
+			mob->dropitem[c].nameid = item_id;
+			mob->dropitem[c].p = (rate > 10000)?10000:rate;
+		}
+		else //No place to put the new drop
+			return 0;
+	}
+	else {
+		ShowWarning("addmonsterdrop: bad mob id given %d\n",script_getnum(st,2));
+		return 1;
+	}
+
+	script_pushint(st,1);
+	return 0;
+
 }
 
-BUILDIN_FUNC(delmonsterdrop)
+/*BUILDIN_FUNC(delmonsterdrop)
 {
 	int class_,item_id;
 	class_=script_getnum(st,2);
@@ -18051,6 +18080,7 @@
 	BUILDIN_DEF(disguise,"i"), //disguise player. Lupus
 	BUILDIN_DEF(undisguise,""), //undisguise player. Lupus
 	BUILDIN_DEF(getmonsterinfo,"ii"), //Lupus
+	BUILDIN_DEF(addmonsterdrop,"iii"), //Akinari [Lupus]
 	BUILDIN_DEF(axtoi,"s"),
 	BUILDIN_DEF(query_sql,"s*"),
 	BUILDIN_DEF(query_logsql,"s*"),