Addiction and the abuse of intoxicants

A character hooked on any intoxicant pays a steady price. Every two months he or she must save vs Constitution or lose a point of it, permanently or until the habit is broken, and once a year must save against each other attribute or lose a point there as well. A monthly Constitution save that succeeds means tolerance has set in, and the dose has to go up by 25% to have the same effect.

Missing the daily dose brings a save vs Constitution every six hours to hold off withdrawal. The symptoms come in stages: heavy sweating for 2-12 hours, then violent shaking for 2-12 hours (all combat rolls and DEX saves halved, and a 50% chance for casters that any spell fails), and finally crippling pain broken by bouts of exhausted unconsciousness for 1-3 days. Once these pass the character has kicked the habit. Taking the substance ends the symptoms within 2-20 minutes, but keeps the addiction going.

Even a recovered addict must save vs WILL whenever the substance is nearby, with +1 for each month of sobriety. A failure means giving in and taking it; a second failed save vs WILL means the character is addicted once more.