Siege Engines are common in fantasy works and alternate histories. Also appear in Historical Fiction. Often part of a literal Storming the Castle arc. * Catapults: Simple constructions designed to fling projectiles, which can be pretty much anything. * Ballistae: Basically a giant crossbow. Often lit on fire. Invented by the Greeks, but most extensively used by the Romans. * Trebuchets: A giant, usually non-portable sling catapult with a very long range. (Not Tree Buchets) * Siege towers: Large wheeled and armoured towers with ladders or stairs inside, designed to provide access over high walls. * Battering rams and screws: For knocking down or breaking through gates, and less commonly used on stronger points in the wall. * Vats of boiling oil or molten lead: For coun