A fast and balanced alternative to standard Energy Drain attacks.
In the official rules, Energy Drain (RC/154) attacks reduce the victim's experience level; while terrible in effect, this can bog down play as the target re-calculates hit points, THAC0, spellcasting capability, etc. To streamline play, consider reducing CON instead. For every experience level normally lost by a successful energy drain attack, reduce the victim's CON score by 1. For example, a wight's touch reduces CON by 1; a vampire's energy drain reduces CON by 2.