 Billiards are a particularly well-studied family of models. Think of a perfectly flat billiard table and assume that the billiard balls bounce off the edges of the table elastically. Such a model table at the macroscopic scale of our experience where the balls and edges are characterized by classical mechanics is called a classical billiard. Lots of analytic results have been worked out for classical billiards so this is makes billiards a very attractive model to study. A chaotic billiard is a classical billiard where the conditions lead to chaotic behavior of the balls. There is a wealth of results for chaotic billiards, too. Such analytical and computational riches have made quantum versions of billiards workhorses for studying quantum chaology as will be seen below. One can produce quantum billiards by using Schrödinger’s equation to describe particles reflecting off the boundaries (where one specifies that the wave function for the particles is zero at a boundary), or one can start with the equations describe a classical billiard and quantize the observables (e.g., position and momentum) yielding quantized billiards. 