AFAIK all editions of D&D limited character advancement to one (or 1.99999, but never 2) level(s) at a time, but I can find no such rule for Pathfinder. If PCs earn enough XP in a single game session/game day/other appropriate period to advance two levels, then they do so?
I don't recall that rule from any 3.x version. There's certainly no reason why some arbitrary period of time should have to pass between gaining levels, aside from the headaches involved with gaining levels mid-session.
I don't recall that rule from any 3.x version.
PHB v3.5 pg 58 under XP and Levels.
I don't recall that rule from any 3.x version.PHB v3.5 pg 58 under XP and Levels.
Huh. You're right, I missed that.
Well, as part of the OGL, Paizo had to redo the entire XP system. So that rule's no longer around, and good riddance. If the GM wants to award enough XP that you gain two levels, there's no reason you shouldn't gain two levels. And how long does an "adventure" last, anyway?