Arbalest

An arbalest is a large crossbow-like siege engine, similar to a ballista, except that the arms are a single piece (of steel or wood) that flexes like a bow. It is derived from the French term arbalète à tour.

They are a popular for SCA combat because they are relatively simply to build and operate, are portable, break down to a compact package for transport to and from an event, and may be used in direct-fire against massed troops as well as against structures.