What level are the characters supposed to be at the start of Fortress? I cant seem to find it....
http://paizo.com/pathfinder/adventurePath/riseOfTheRunelords/v5748btpy80hm
For characters of 10th to 11th level.
According to the Anniversary Edition:
Advancement Track
11th Level: The PCs should reach 11th level during (or just after) the attack on Sandpoint.
12th Level: The PCs should reach 12th level by the time they're infiltrating the interior of Jorgenfist.
13th Level: The PCs should be 13th level as they finish exploring the pit and caverns below Jorgenfist.
Concluding the Adventure: The PCs should be close to (but not quite) 14th level at the conclusion of this chapter.
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Which means the PCs should be around halfway into 10th level when they begin the adventure, and almost 14th level when it ends.
Is the Anniversary Edition that much different? According to the
5th module("Sins of the Saviors"), the players should be 12/13th and the
6th module("Spires of Xin-Shalast"), the players should be 14/15th. That's quite a jump.
Is the Anniversary Edition that much different?
Yep. In the Anniversary Edition PCs should wind up just shy of 18th level.
Double yep. The first two modules are pretty much the same in the Anniversary Edition, but starting about halfway through Module 3 everything starts to be adjusted.
Keep in mind, the original used the 3.5 advancement coupled with the fact that many creatures have had their CR revised in the Pathfinder rules (which means different XP awards). All on top of the fact that XP awards are determined differently in PFRPG as well. These elements combine to shift the advancement track ever so slightly in the beginning but over time it accumulates to a major shift near the end.
Plus, there are a fair amount of new encounters and Story Award bonuses that were not in the original. Most of these are in the later half of the revised campaign.