I have seen this term appear on various gaming forums, but I cannot find a source for its origin, or a clear definition for it. What does it mean?
Here is an example: the term appears as part of the definition for "rules light" in the RPG Glossary at RPGGeek, but is not given any explanation in its own right:
Rules-Light - Having few rules, leaving much up to player fiat and/or social contract.
I know what GM fiat is. Is player fiat just the opposite? People don't seem to use it that way. I only just started seeing it crop up in the last few months and I'm not sure where it's coming from or what it is.