Paizo Posts Pathfinder Perrata... I mean, Errata. As an editor, I know just how tought it can be to make sure a book is right when it goes to print. With easily dozens of versions of documents flying around, it's easy to have a version get sent that wasn't entirely what you wanted. Be it typoes that just didn't get spotted, rules that had been updated but the wrong document sent, or often just rules that seemed good at the time, but once you get them out there don't quite work how you wanted. Whatever the reason, an update is necessary, and that's just what Paizo's posted for you.
From the post:
The Pathfinder Core Rulebook has been out in the wide world for a few months now! While you’ve had a chance to put the game through its paces, we’ve been hard at work combing through feedback and questions from staff, players, and fans of the game, looking for any spots that need clarification.
As with any publication, we’ve found a few errors along the way, and we’ve been carefully collecting and compiling them. While we’re not going to list out every typo that we’ve now corrected, we want to provide everyone with the most central updates to the text of the game. Some of these are rules clarifications or corrections of simple errors, while others are broader changes to streamline play or bring core concepts of the game together. We’ve also provided a brief explanation of each change to help show our intent so you can more easily apply the changes to your game.
We should note that not every problem has been addressed in this document. Some are a bit complicated, and the solution is going to take more time to fully test before releasing it to all of you. Just because you don’t see an answer here doesn’t mean that we aren’t aware of and considering the issue—we’re likely just trying to figure out the best way to handle it. Please also note that this document contains updates for only the Core Rulebook. We’re still vetting some changes to the Bestiary and some other products, and we’ll get those changes out to you as soon as possible. Thank you for your understanding and patience as we work to make Pathfinder the best game it can be!
You can find a PDF download of these first official errata here.