Lag is a stimulant drug which enhances the user's perception and metabolism, effectively speeding up their movements and thought processes. From the user's point of view, everything around them seems to slow down (hence the name "lag"). In game terms, the user can act twice in each combat round, taking one action before non-users have taken a turn, and the other afterwards. If there are several users in a combat they go, relative to each other, in dexterity order.
The effects begin 4d rounds after the drug is taken, and last for 12d rounds. Once the effect has expired, the user will be exhausted and takes a -2 penalty on all rolls until they have rested for at least 8 hours.
The drug is mildly addictive (throw 3d: a result of 18 exactly indicates addiction). Addicts suffer a penalty of -1 on all rolls per day they have not taken the drug, cumulative.
Lag is made by Sutton Pharmaceuticals. It is illegal almost everywhere except where used by military or law enforcement personnel. A typical dose of 0.5g costs at least Cr 500 on the black market.