Has there been any sort of consensus on exactly what range of depths/areas the Book of Dark Rituals can drop in?
I've heard it's anywhere in T3, only in Stratum 6, only in Arcade (missions taking place in T3 don't count), only in Shadow Lair...
Especially with the new patch lowering the chances to get a book, it's worrisome to wonder if I'm even hunting in the right possible areas (currently running a lot of Alone in the Dark).
Someone got one in the Weight of Darkness Mission first depth. Try dat.