Randomness in Roguelikes

I think there is a feeling here of either I have this bounty of stuff to play with by the time I get to the holy mountain, or oftentimes just not. Some of it might be like, you just don't go to the part of the level that has the wand. It's clear to me that they have not just thrown up their hands and randomized everything. Like, clearly there's some attempt there to wrangle randomness. And I'm curious about where they drew the line there.