"God-Machine Chronicle Rules Update" is a rules revision for the new World of Darkness. Historically it was a all-but-in-name new edition. It is now actually a new edition, known as nWoD 2nd Edition.
Its differences from the New World of Darkness line (1st edition) are more pronounced than from dnd 3.5 vs 3.0. Questions should not be tagged with both nwod and nwod-god-machine, unless unless it applies to both, setting questions are a good example of this.
The God Machine Chronicle Rules Update
The God Machine Rules Update (GM-RU) was first released as an appendix to the "God Machine Chronicle" setting/story book. It requires the requires the World of Darkness Core Rules (from base nwod) to be fully playable. While it changes many many rules, such as adding conditions (which partially replace Flaws and Derangements), changing the XP system significantly use Beats, modifying combat damage. Some content such as skill and attribute use has not changed and can only be found in the nWoD Core books -- or in one of the fully stand alone god machine books such as Blood and Smoke.
However most content from earlier nWoD can not be directly ported (without modification). In particular merits can not. However the GMC-RU includes a "best of" collection of merits from a variety of nWoD books (Such are Armoury and Second Sight), converted and updated to the new system.
The God-Machine Rules Update is available as a free download.
Books that are or will be compliant with the God-Machine Chronicle rules
- God-Machine Chronicle (A setting book with the GMC-RU in the appendix, thus requires nwod core.)
- Vampire the Requium 2nd Ed (Also published as Blood and Smoke: The Strix Chronicle), fully standalone but fully compatible vampire-requium-2
- Demon: the Descent (a new supernatural template book, GMC-RU in the appendix.) demon-the-descent
- Werewolf: the Forsaken 2nd Ed: Formerly marketed as "The Idigam Chronicle" (not yet released)
- Mage: the Awakening 2nd Ed: Formerly marketed as "The Fallen World Chronicle" (not yet released)
- Mortal Remains (Conversion guide for mortals/Hunter. It can also be used to supplement a existing nWoD game without converting to God Machine Rules.)
Does Blood and Smoke invalidate previous Vampire books? -- including how God Machine invalidates existing books