Unisystem

Unisystem is a generic role-playing game system produced by Eden Studios, Inc.
Unisystem was developed by C.J. Carella for the first editions of his WitchCraft and Armageddon role-playing games published from Myrmidion Press. Eden Studios uses Unisystem under an exclusive license, but has offered other game companies to license the system from them. Eden Studios published WitchCraft 2nd Edition and their original All Flesh Must Be Eaten games as Unisystem games. Armageddon 2nd Edition and a new 2nd Edition of Eden's own Conspiracy X were later published, also using this gaming system.

Two major branches of the system exist: Full Unisystem, and Unisystem Light. The major difference is that the Unisystem Light games generally require no dice rolls by the GM, instead using fixed values for NPC's. Buffy, Angel, and Army of Darkness are all Eden Games Unisystem Light offerings. Further, Unisystem Light also uses only ten-sided dice, while the full Unisystem uses a variety for damages.