Nillen's Pharmacy is the go-to place in Alacria for high quality narcotics.  One of the most potent drugs Nillen provides is Zero.  Many depressives, schizophrenics, psychotics, and others who suffer from debilitating mental illnesses become quickly addicted to Zero as many describe the drug as "removing all the voices in your head," allowing you to more fully experience the physical world around you.  Withdrawal from Zero is very nasty and overdoses are unfortunately common.

Recently, Nillen has jacked up the price of Zero, both as a way of controlling the number of ODs so that Alacrian authorities won't be forced to apprehend her but also, since it is so addictive, making more money off the addicts desperate enough to get another hit.

Consumption

When you take Zero, your Intelligence score drops down to 2 until you take a long rest.  After a long rest, gain one point of exhaustion and make a Constitution saving throw (DC is 3 x the total number of times you've taken Zero).  On a success your Intelligence score resets.  On a failure, you become addicted.

Addiction

Upon failing the initial Constitution saving throw, you advance to the first stage of Zero addiction (see below).  After each long rest, make a Constitution saving throw (DC is 3 x the total number of times you've taken Zero + the number of long rests that have passed since you've become addicted).  Upon a success, you will no longer suffer future effects of Zero addiction, but your addiction is not cured until you feel the effects of a Greater Restoration.  Upon a failure, you will suffer an additional effect for each saving throw that you have failed.

1. You are unable to reduce exhaustion via long rest.
2. You are afflicted with a long-term madness that lasts 1d10 x 10 hours and each of your character stats are reduced by 1.
3. You gain a point of exhaustion and each of your character stats are reduced by 1.
4. You are afflicted with another long-term madness that lasts 1d6 x 10 days and each of your character stats are reduced by 1.
5. You gain a point of exhaustion and each of your character stats are reduced by 1.
6. You are afflicted with an indefinite madness and each of your character stats are reduced by 1.
7. Death.

Taking another dose of Zero while you are addicted gives you the effects of taking a single dose, as well as advancement to the next stage of the addiction.

Overdosing

You can take a number of doses of Zero equal to your Constitution modifier (minimum of 1) per long rest.  If you take more doses after surpassing this limit, you run the risk of overdosing.  In this event, make a Constitution saving throw (DC is 20+ the number of doses exceeding your Constitution modifier).  Upon a success, you automatically become addicted to Zero, gaining the effects of a day 1 Zero addiction (if you are not already addicted) or advancing you to the next stage of Zero addiction (if you already are addicted) and are incapacitated until you take a long rest.  Upon a failure, your hit points are reduced to 0 and you have disadvantage on death saving throws.  Additionally, the Medicine check to stabilize you increases to DC 20 minus your Constitution modifier.

Notes: Set: Intelligence Score, Debuff, Consumable