Certain drinks and foods, and almost all chems have a chance of addiction. Should a player become addicted to a substance, then they will crave that material for a determined period of time until they either kick the addiction, get cured, or satisfy their craving. Every time an addicted player takes his dependent chem, the time to kick the habit is reset. The craving translates out to a long debuff that is equal to the drug's Down Effect. If a substance has no down effect, then simply use the debuffs in the substance's regular effect. To determine addiction chance after stats modifier, simply subtract the player's EN from the listed addiction chance. Should you have a trait or perk that modifies addiction chance, multiply the addiction chance by this before subtracting EN.