So what’s this? It’s a port of the tabletop role-playing game Mage: the Awakening for the rules-lite Risus RPG system. It’s intended for people who are familiar with Mage but want to run it on a lighter system, or possibly for people who want to run pick-up games without having to go through the somewhat laborious character-creation process that is part of the Storyteller System. It’ll help if you have a reference copy of the Mage corebook (and, for supplemental materials, the extra sourcebooks for the game, e.g. Tome of the Watchtowers, Tome of the Mysteries, Summoners, etc.), and you should also download a copy of Risus and familiarize yourself with how the system works before you start. (Don’t be afraid! It’s like six pages long, seriously.)
What this isn’t is a replacement for the Mage book. It’s really pretty, you should get it, and it has a lot of the background stuff/extra bells and whistles that are really handy if you like the game.