Though I forgot about this, did you? It's just that a lot of my writing time was taken up by RGPaDay. And now I'm back to this.
Now that all of the character details have been described, it's time for the combat rules.
Like a lot of other things in 13th Age, there's not a lot of detail, but for the most part, that's fine. It's supposed to be the "good parts" version of D&D, and obsessiveness about tactical detail is "unfun."
A couple of things that I didn't mention in the characters section do become relevant and discussed in more depth here. First of all, weapons do their damage die per level, so as you advance, even the fighter needs to worry about rolling buckets o' dice. That longsword does 1d8 damage at first level, but 5d8 once you make to 5th. Once you get to 10th level, you could be rolling 10d8 for a successful attack with an ordinary longsword. So this is where the book offers tips to manage large amounts of dice.
Also, characters have different Defenses instead of saving throws. Whoever makes the attack, whether it's a strike for damage or a mind affecting spell, rolls the dice instead of the subject of the effect rolling to resist it. I think this was a 4e innovation to make everything consistent, but 5e got overtaken by nostalgia from earlier editions and saving throws came back.
Then we get to the next big innovation of 13th Age: The escalation die. It doesn't have to be a die, just a way to track a value from 1-6. Basically, it goes up every round of combat until 6, where it stays if the bad guys aren't dead yet. The number on this escalation die is added as a bonus to PCs attack rolls, giving them a little boost even if their dice aren't on their side. There are also character and monster powers that engage when the escalation die reaches a certain point.
The GM chapter opens with advice on using the Icon relationships, which more or less demonstrates that the whole idea is really neat, but not fully baked. They suggest that GMs can use Icon relationships to add in plot twists, or allow players to add plot twists (more as a "get out of jail free" card), or even just have them manifest as cool stuff that the Icon connection gives the character access to. They then take this lack of clarity even further by openly suggesting "Once we publish this, people will figure out their own way to make this mess sort of work! Check the internet!"
We spend spend the smallest amount of time possible on some topics that the designers don't care about, dealing with skill checks and traps/ Then something that the designers care about: building battles. D&D has had encounter building rules in several editions intended to create a sense of balance or fairness into the proceedings, and this is no different. Though they do follow up their "fair fight" rules with suggestions to make things "unfair" and therefore more interesting.
Now we get to the rules for leveling up and one of the things that kinda kills my interest in this. And that is the fact that there is no XP. I understand the reasons behind this. It reduces the bean-counting in the game and the longstanding convention of XP for monster kills is not conducive to productive play. which has been known and understood pretty much since it was first implemented.
Maybe I'm spoiled on storygames, but even more traditional games will offer up some sort of Drama/Fate/Cool Point for leaning into the genre, doing cool stuff, or just making the GM laugh. While Icon Relationships can kinda sorta be that, it's also kinda sorta a lot of other things too.
Earlier in the book, it mentions that it uses alignments throughout the book as a way to define characters, but you don't have to. In fact, you can borrow the character description tools from other RPGs if you want. They mention Burning Wheel's Beliefs and Instincts, but you could also do things like character Aspects from Fate. And that's a problem, because those aren't just methods of describing your character's personality, but are also backed by those sorts of Drama Point mechanics.
It's just another point in the "Did they really think about this before writing it down?" column, really.
So the lack of XP sets up two issues for me.
1) The lack of mechanical incentives reduces player engagement/agency. While there are many ways to reward characters and get them involved in the action of the campaign, 13th Age leaves that largely in the hands of the GM rather than the rules. Not that this is necessarily bad, but it puts an extra burden on the GM, in my opinion.
2) If advancement isn't about rewarding players, it instead acts as a pacing mechanism, setting up how quickly the campaign escalates. Making the call on how quickly to advance with only 10 possible steps can be a challenge for the less experienced GM.
They do address some of this by providing for incremental advancement, breaking each level into 5 or so stages, so there are 50+ breakpoints instead of 10. They also discuss the idea of the 10-session campaign, where the party advances after each session.
Now they get talking about treasure acquisition. And again, because it's a major source of bean-counting, they do their best to avoid it. You can get minor loot from various things, but magic items are serious business. They're not detailed here, but we are assured that they are.
Then there's a small discussion about rituals, which are basically spells that are cast out of combat. Some of the designers here worked on D&D 4e, so having the game focus on cool combats and kind of shoving everything else off to the side feels about right. So spellcasters have their combat capabilities well structured, but ritual casting is much more loosey goosey.
There are also small sections discussing the Icons and the gods of the setting. Icons are big, but also kinda vague. You can also make up your own Icons if you want, but the ones that are there make a pretty good set. The gods are just sorta there. They need to exist for the cleric and paladin classes to work, but most of their role in the setting is taken up by the Icons. If you want to use them in a story, you can.