Using Drugs: Unless otherwise stated, Drugs require a Combat Action to administer.
Requisitioning Drugs: At the beginning of a mission, you may attempt to Requisition Drugs in place of Ammunition or other Consumables. Each Requisition is enough to acquire a number of doses equal to 5 minus the Drug's Rarity modifier.
Excessive Drug Use: When the same drug is used too often in a short period of time, there is a chance for it to have a diminished effect as the user builds up immunity or tolerance.
When you use more than one dose of a given drug in a 24-hour period you must make a Resistance Test (Toughness; DN 3) for each use after the first, with a cumulative +1 DN penalty for each additional dose. If you fail, the drug has no useful effect and further doses do nothing for the next 24 hours.
Addiction: Excessive drug use can also lead to Addiction. Every time the effects of a drug indicated by the Addictive (X) trait wears off, you must make an Addiction Test; this is a Willpower Test with DN equal to (X). Failure means you have become addicted to the substance; you suffer a +1 DN penalty to all Tests, and you suffer one point of Shock unless you get another dose within 12 hours (should this dose trigger the Excessive Drug Use test above, you must pass the Resistance Test to overcome the Shock). Addiction cannot usually be cured through the use of the Medicae skill or medical treatment, only through long-term abstinence.