Potionless conduct, which prohibits the hero from using or breaking a potion (i.e. quaffing them, dipping things into them, throwing them; also breaking them with a force bolt). Monsters throwing potions at you or breaking potions with force bolts do not break the conduct even if you breathe the vapors, which does mean there’s some possibility for abuse in putting a potion on the ground and giving a nearby intelligent monster a wand of striking, but the alternative is too strict.