[SPOILERS] The new room in p10

[kNightCrawler]

Just found one of these in UD:3.
As said in the OP, they're announced by the message "You feel a surge of pulsing power!". Didn't manage to get into the room, though, since my char had no means of digging and ended up dying to a spider factory soon afterwards anyway.
According to the death log, the Black Tome was generated. Ah, well.

[anon123]

That was on prerelease 13/14, I presume?

A couple of days ago, I managed to take a pr10 Chaos Knight several levels below the Casino, before fluking him by forgetting I had the freezing blood corruption while clearing a white dragon vault... anyway, didn't get a single artifact room (although Leggot had the BoW, and a giant in the banshee level dropped Celestrix ). I think they should be made to spawn a little more often, perhaps add a guaranteed one. That would make a fourth or fifth guaranteed random artifact in the game, but since 1.2.0 is going to add a ton of new ones, I don't think that'd be terribly unbalanced.

[kNightCrawler]

It was in pr14.
Yeah, it sure would be nice to see maybe a guaranteed artifact room somewhere... so far as of pr10 I've found more artifacts randomly dropped in vaults (including Skullcrusher in pr11 and Perion's mithril plate mail in pr14) than actual artifact rooms :P

[wopp3]

Old thread, but first time I stumbled up one of these. And it was in D1 - a named water demon against my level 10 wizard -> me dead in 2 turns. Other creatures in the room were quite easy Ogres and Giant Bats etc.

From the death screen it seems my artifact would've been Wyrmlance; so not worth my early death this one