Changes

The most fanatical players go for this variant. BNMs use equipment, but only equipment with negative stats. Plenty of items in Diablo and Hellfire have -stats, lowering attributes, mana, hit points, etc, and these are what BNMs use. Whether your character must equip every such item found, or just one or two, varies depending on how purist a rule set you follow. In any event, the end result of using cursed equipment is lower mana, since there are no mods in Diablo or Hellfire that change casting speed, lower spell levels, etc, so all a BNM is doing to himself is lowering his attributes, mana, and hit points.

A high level Sorcerer will have maxed out his Fireball skill, and is willing to deploy appropriate magics on a hair trigger. Sorcerers have very high mana and very little patience, and are known to teleport more than they walk. They also know that overkill with spell use is safer and actually mana-cheaper than being stingy with the spells and taking hits because of it, so they tend to spam their Fireballs and Chain Lightning until they're quite sure monsters are dead. Expert Sorcerers dart through the Hell levels, teleporting from room to room, hugging the walls to optimize the performance of their Chain Lightning, making daring teleporting runs through large areas to draw all the monsters into killing zones, playing never more than an inch or two out of reach of the enemies, and drinking blue pots like water.