Changes

The large central room in the Chamber of Bone has the highest density of monsters anywhere in the entire game. There are at least 70 or 80 skeletons packed into the room, along with about a dozen Hidden. They are not powerful monsters, and have only a single doorway to exit through through, so most characters are able to treat this like a bonus quest. Stay right at the doorway during the battle, even if you take hits, since the skeletons will otherwise pour forth like sand from a broken hourglass. It's wise to clear out the rest of the small level before taking on the large bone room too, just so no Hidden or Chargers will wander up behind you while you're engaged with the never-ending stream of skeletons.

Spells with splash or area effect are quite useful here. A single firewall can kill dozens of skeletons, and some well placed flame waves can take out the rest in short order. Also, be careful moving into the room; just standing in front of the doorway will not alert two rows of skeletons against each side wall, and an overly-rapid advance into the bone room can result in a surrounded hero.