This book was pretty much exactly what I was hoping for when I read Magic: A Manual of Mystic Secrets - a list of new spells and magic items for the Earthdawn universe. And I was right to want something like this, because it was pretty good.
No, I should probably do just a little bit more to justify my existence here. That's probably going to involve me nitpicking the parts of the book I didn't like, because if I focused on the parts I did like it would just be me pointing at spells and going - ooh! Seriously, these are some of my dullest notes in ages. They're mostly just a list of spells. "Billowing Cloak" - ooh! "Mist Balloon" - ooh! Sometimes, I'll mix it up, as with "Bone Pudding," where I added a "yikes!" instead (because, instead of making your cloak billow dramatically or create magical balloons to lift objects off the ground, it turned your enemies' bones into a pudding-like substance - yikes!). All-in-all, it's a pretty good spell list.
If I'm going to complain about anything, it's the fact that we are getting expanded content for the classes that need it least. It's the Tome of Magic all over again. Spellcasters got disproportionate space in the core book, and now they're getting half of a supplement too (plus the spellcaster-relevant material in the magic item section). I mean, I understand the impulse, because in a fantasy world magic spells are often critical setting material, but I feel like drawing such a clear distinction just winds up leaving a bunch of your character types out of the fun.
Although in fairness to Arcane Mysteries of Barsaive, it does remember that technically all Earthdawn characters are magic users and subsequently devotes about ten percent of its length to new Talent Knacks. However, Talent Knacks continue to be a system that feels like an afterthought. They're all generally nifty to have, but it's tough to see where they fit in an overall build strategy (though I'll admit, part of this may be my own inexperience with the system).
Earthdawn is sometimes frustrating to me, despite how much I generally like it, because it often seems like an inflection point between AD&D and Exalted. Like, if you had a gaming group that was even split between people who wanted to play AD&D and people who wanted to play Exalted, then Earthdawn would be the ideal compromise candidate. AD&D has this thing where it likes to pretend that high-level fighters and thieves are completely nonmagical and that the high-level numbers that allow them to fight dragons and shit are just the result of swording better. And Exalted has the opposite tendency where you buy your Martial Arts skill up high enough and suddenly you qualify for charms that allow you to sword the concept of time. And then Earthdawn comes along and says that the reason you sword so well is because you know magic, but that mostly what you do with your swording skill is sword with better numbers.
It's a tenuous balance. I went back to the core and did some calculating, and you can almost build a Warrior Adept who is functionally the same as an AD&D Fighter. The Melee Weapons Talent is exactly the same as a mundane Melee Weapons Skill, just with a cheaper XP cost. Same with a lot of the Discipline's other Talents - Avoid Blow, Second Attack, Cobra Strike - they could all easily fall under the category of "swording better." There are a couple of bottleneck levels where you can't get past them without picking one explicitly magical ability or another, but even then, if you're willing to tweak the aesthetics of Stone Skin to just being unusually tough, that's not much different than having 15 levels worth of hit points and being able to tank the dragon's breath.
In the other direction, it's tougher, but not impossible to make your characters more like Exalted-style anime protagonists. Warriors could also buy the Air Dance Talent at level one, allowing them to slide around the battlefield on a cushion of air. The problem is that Air Dance starts at rank 1, and takes significant investment to actually be good (and even then, its primarily utility is as an initiative booster). Contrast that with something like Graceful Crane Stance, which is a starting-level power that lets you use magic to balance on a leaf - and it just works. There's a sense I get that Earthdawn doesn't quite understand that its premise means that Adepts have permission to be awesome and weird. Why, for example, is Billowing Cloak a spell and not just something a Troubador can do?
That's, ostensibly, what Talent Knacks are for. Take the "Bounce" knack and a Warrior can use their Avoid Blow power to mitigate falling damage. Mimic Music allows a Troubador to hum so it sounds like a fiddle or a grand piano (or whatever). These are neat little binary abilities that can serve to make your Adept feel more magical. The only problem is that they're very clearly written in a way that signals they are not meant to be a part of your character's core capabilities. They all require hit points to activate! And even though this book corrects Magic: A Manual of Mystic Secrets' inexplicable decision to not allow you to develop your own knacks, it does so by charging you double xp for them. They are obviously meant to be a dip, which makes it all that much tougher to decide between the dull-but-effective options, like Armor Beater and the cool-but-weak ones like Improvised Weapons (beat someone to death with a loaf of stale bread!).
Also, the Talent Knacks are organized alphabetically, instead of by Discipline or Talent name, making them needlessly difficult to purchase. They're like Charms done poorly (and if you're not familiar with the mess of Exalted Charms at their worst, that's saying something). Does that mean that I'm going to do some sort of bizarre and hideous Earthdawn-Exalted hybrid that takes inspiration from the Charm system to make Talent Knacks more openly fantastic?
No, I just needed something to keep this post from being an obnoxious lovefest ("City in a Bottle" - ooh!), unless . . .
Ukss Contribution: One of my most arbitrary decisions yet. This entire book is just a list of neat fantasy ideas. Some are neater than others (for example, I'm not sure why Illusionists need both a "Blindness" and a "Blinding Glare"), but it's a generally strong set. I can't really pick a favorite, so I'll just go with the one that has the strongest setting implications - Council of the Forest. You cast it in the forest and it summons every significant plant spirit in a 1-mile radius. You don't control them, they'll just come to your location and debate you (well, more like "hear your petition concerning matters of importance to the forest," but the debate is pretty much inevitable).
There will probably just be one Council of the Forest in Ukss, tied to a specific location, but there will definitely be a magical ritual that lets you summon it into session.