Board Thread:Suggestions forum/@comment-27991709-20160801171429/@comment-25841881-20160801193141

(Or click his link and read.. Alte's right.)

On topic.. Burning oil is a common idea, but actually not that practical as a defense.. Dropping a rock works as well as dropping burning oil, and is much cheaper and easier.. You don't have to find or produce some sort of oil, you don't have to take care in not spilling it, you don't have to be careful not to burn yourself.. You just have to go find a nice-sized rock(or rather, get it from the quarry before it is used..) and then carry it to the top of the wall.