The most significant shift in gameplay introduced in this edition come from monster damage expressions. Playtest feedback, and our own games, indicated that our original all-dice monster damage system was swingy. Too swingy, unless the GM implemented dice conventions on the fly.
We’ve finally adopted the system Jonathan has always (3e, 4e, homebrew, 13th Age) used for monster damage in the games he runs: fixed damage amounts for most monster attacks. See the start of the monster chapter for the full rules and discussion of the rationale. People who want to roll dice for monster damage can, but we’re opting for something cleaner.
Other changes include many new or fixed-up monsters, redefinition of ‘vulnerable’ and vulnerability, a reorganization of chapter 6: Running the Game, more shifts in the racial abilities including a new racial curse for tiefling, an icon alignment chart dropped colorfully into chapter 2, adjustments to the barbarian and cleric . . . . and the difficult decision to pull the monk and multiclassing out of this book.
I’d already realized that multiclassing was almost certainly going to be something that we should calibrate when we had a perfect sense of our published play balance. Then our developer’s input on the previous copy of the Escalation Edition was that finishing the monk properly would take almost as much time as finishing everything else in the book.
I’m making the call that it will be better to publish the game sooner rather than push the monk to be another part that works and publish later. So the monk is going to get finished after everything else and published in another book. It’s not ideal. But it’s better than screwing it up. We have high design ambitions for both the druid and the monk and as usual, if we err, we want to err on the side of getting it right [Publisher's Note: There is also the issue that the book has far more content already than when we priced it - so you won't be losing out. It's a big book!]
We’re still getting good playtest feedback from people who are using the Escalation Edition. Send concise playtest feedback to 13thAgePlaytest@gmail.com. One of the last things we’re going to do is comb back through all the playtest comments and compare them to our final manuscript, so if it seems like we haven’t accounted for your comments yet that may be true.
[For more on the monk and the forthcoming 13 True Ways see this interview on rpg.net.]