Imperium Offtopicum is a broad category of geopolitical role-playing games hosted on the Civilization Fanatics' Center. The first instalment, Imperium Offtopicum I, was created by Taniciusfox in response to the anarchic OT Poster Empires; originally located in Forum Games and following a linear sequence, the series spawned so many sequels and spin-offs that it was eventually given its own subforum.
Rules, regulations and general gameplay can vary wildly from thread to thread. The first three games (IOT1, IOT3 and IOT4) were largely open-ended with few set mechanics and a mostly impromptu method for simulating combat. Later games introduced national economies, technological development, standing armies, natural resources, and/or a host of other features at the discretion of each particular game moderator. In general, IOT aims to be less scripted and "computational" than the somewhat similar Never-Ending Stories, and has been described as an even lazier "Lazy NES".