Random rooms

[create]
room_list=ds_list_create()
ds_list_add(room_list,room1,room2,room3)//You can add up to 16 rooms in one function, if you need more then add more:
//ds_list_add(room_list,room17,room18,room19)

[your change of rooms]
if(!ds_list_empty(room_list))
{
ds_list_shuffle(room_list)//Shuffle to get random rooms
room_goto(ds_list_find_value(room_list,0))//Change room
ds_list_delete(room_list,0)//If I remember right this will still be executed
}