Arson classification efforts are an attempt to make sense of a complex whole. To a greater or lesser extent typologies offered to date have relied on assumed motive. More recently, systems that combine information about offender characteristics and/or offence features have become increasingly popular. The ability to categorise arsonists accurately has significant implications for both mental health professionals and fire authorities. It is important to understand the limitations of arson classification systems generally to be able to apply them judiciously. This article discusses arson classification systems and examines three key approaches before providing an overview of some of the limitations of arson typologies generally.