The Book of Artifacts is AD&D giving itself permission to make its magic items good.
Okay, that's an uncharitable way to characterize the book, but I don't know what to do with it otherwise. It's so serious about its "innovations." An Artifact is a magic item with a history. An Artifact is a magic item that plays a role in the story. And . . .
I don't know. The year is 1993. The end pages have advertisements for six different campaign settings. How are you just figuring this out now?
Make no mistake, the Book of Artifacts doesn't quite figure out magic items. Not even special Artifact-level magic items. It's filled with problems. By and large, the Artifacts themselves are all great (with notable exceptions like The Regalia of Might - no one knows what an "Orb of Neutrality" is supposed to be, and no one will ever know, because it's a hardcore D&D-ism that only makes sense if the game's rules are also its setting), but then they are immediately undermined by leaving a significant fraction of each Artifact's powers up to a random dice roll.
Congratulations, you have just found an ancient magitech battle robot - roll 14 times on three different tables to determine what its powers are.
AD&D as a whole is too enamored with randomness, and the chaos it might cause, and it is especially destructive here, in a book that is ostensibly about adding curated story elements to a campaign. There are two separate Artifacts which basically amount to "state, in-character, what you are entering into the device's elaborately coded input and then the DM will consult their custom-built cipher to determine whether you are doing something effective, overpowered, or suicidal." I'm sure they made for some memorable campaigns, but sitting here in 2019, looking back, it's like a communication from a different universe.
I'm trying to remember back to my teenaged roleplaying days, and I think I remember games like this. Where some randomness driven magic item, like the Machine of Lum the Mad or the Deck of Many Things would show up and then we'd just drive the whole campaign off the rails trying to exploit them without killing ourselves in the process.
It was a very particular kind of fun. A lot of giggles. But contemplating it today, I can't help but think of it as pretty much giving up on the initial campaign premise and just surrendering to silliness.
The other main flaw of this book is that its idea of "game balance" is based on . . . no earthly logic this reviewer is able to discern. A lot of this comes down to the items' curses. They often seem obligatory, a great many are far more punishing than the item's powers merit, and a few seem like they should be the Artifact's primary function.
Two case studies.
Case #1 - Queen Ehlissa's Marvelous Nightengale.
Its powers are useful, but situational. Mostly some low-level magic slightly more often than a PC priest can cast it and some high-level magic significantly less often than a PC priest could cast it. It plays songs that can give friendly creatures +1 to attack rolls, impose mild penalties to hostile creatures, and inspire emotions with its beautiful voice.
It's a neat, flavorful object that would be a valuable asset to an adventuring party, but ultimately isn't going to elevate them into a new weight-class, power-wise.
It corrupts your mind so you start to think and act like a child, running in panic from monsters, losing sleep because you're afraid of the dark, and ultimately draining your experience levels at a rate of one per month.
Case #2 - Scepter of the Sorcerer Kings
This is an item that almost lives up to the hype. Just possessing it, any magic directed at you is bounced back to its source with 10x the potency. Once per day, it can dispel magic automatically, without a check, and has a 33% of creating a permanent anti-magic zone into the bargain. Also, it has a poorly-thought-out healing/harming ability that doesn't really fit with the item thematically and winds up italicizing the words "heal" and "harm" in a way that misleadingly evokes the spells of the same name, but doesn't actually function anything like them.
But the real show-stopper is its curse. It just does a little thing like banish a randomly-chosen god from the terrestrial realm for 10 days, each and every time its used. So, you know, heal yourself for 2d12 points of damage, throw the entire world into chaos as priests everywhere lose their powers (not to mention whatever terrifying effects come from the gods not being able to do whatever it is they normally spend their time doing) and just incidentally making enemies of an immortal being with nothing better to do than plot your demise for the better part of a fortnight . . . and you can do it up to 10 times per day.
Way to bury the lede, Book of Artifacts. A magical scepter exists with the power to banish a god and you treat it as a side-effect to a magic-cancelling device. Your "campaign use" section gives plenty of bad advice about "mercilessly hounding" the PC you give it to, up to and including stripping PC priests of their powers to punish the PC you give it to.
But it never occurred you that PCs might want to find some way to harness and direct the power of the "curse" to seal away the power of a specific god. Because "heroes adventure to find an ancient artifact capable of binding a dark god" is not a stock sword-and-sorcery plot at all.
Nope, it's just another hilarious bit of AD&D randomness. The curse exists for "the possibility that the mortal owner of the Scepter might, on the 11th day of possession, receive a visit from a very irate avatar!"
What was even going on in the 90s, seriously?
Anyway, the last third of the book is devoted to magic item creation rules of which the less said the better. Six pages on how to recharge limited-use magic items. The rest mainly suffer from being blindered in that curious way AD&D tends to be when it comes to magic. The Book of Artifacts spends 100 pages on magic items with strange and flavorful origin stories and then the last 30 or so trying to chart out exactly what spells a PC must cast and in exactly what order. Maybe it could have spared just a few paragraphs on dwarf artisans forging weapons of legend deep in their mountain halls (despite not having access to the Wizard class) or perhaps master thieves making dark deals with diabolic patrons for items of cunning power.
Anyway, the Book of Artifacts is AD&D at its most typical. Half amazing fantasy flavor, half arbitrary setting and rules constraints, and half chaos-for-the-sake-of-chaos. That this adds up to three halves is my commentary on the state of the book's math.
UKSS Contribution - There's a lot of great stuff here. I'm tempted to go with The Apparatus - a device that can extract, transfer, and split souls. But that's a whole campaign premise in and of itself. You build a whole world around that technology.
So I'm going with my runner-up choice - The Rod of Teeth. Its powers are immaterial. It's an upper mid-tier weapon marred by the fact that it has a 1-in-20 chance of permanently obliterating the wielder's personality every time it connects. But, it is a magical club, studded with human teeth. Gross. Weird. Like nothing I've ever seen before. The horrifying visual imagery has got to be a good fit for something.