Recently started a new Pathfinder group, running the Rise of the Runelords anniversary edition. Unfortunately, had a MUCH larger turnout of players than expected, and for various reasons I can't split into 2 groups, and can't tell people they can't be a part of the group.
So now I have a group of 8. I attempted to compensate by doubling the number of creatures in the encounters, but the party still handled it easily, with the exception of a trend of horrible attack rolls. But it took too long, the opening encounter of Runelords taking close to 3 hours.
In addition to the doubling, I am using the Critical Hit deck for all monsters, and using the Critical Fumble deck on players only, and dropping the party from the fast track to medium track experience progression.
What is a better way to scale this AP to handle such a large group?