U.S. District Judge Richard L. Williams' ruling that the Army could be held responsible for serving liquor to a soldier who was later involved in a fatal accident was based on a legal theory known as dramshop liability, a concept that is becoming an increasingly popular weapon in the fight against drunk driving.

Taking its name from an 18th century word for saloon, dramshop liability holds that a business that willfully and knowingly serves liquor to an intoxicated customer who later causes a traffic accident can be sued for damages by the accident victims.

So far, 38 states and the District of Columbia have adopted dramshop liability either by statute or by judicial rulings. Maryland's courts do not recognize dramshop liability, and the impact of Williams' decision in Virginia remains uncertain.

Massachusetts attorney Ron Beitman, who publishes a national newsletter on the subject, said that "there is a general consensus that there has been a 300 percent increase in dramshop suits in the past calendar year." He said that 70 percent of those cases get settled out of court.

In the Virginia case Williams found the government negligent because the night of the accident bartenders at the noncommissioned officers' club at Arlington Hall Station served hard liquor to Patrick M. Patterson even though, at 19, he was underage for such drinks in Virginia and was clearly drunk.

"By serving such a large quantity of hard liquor to an intoxicated, underage patron without regard to the potential consequences, the NCO club breached a duty it owes to the community: the duty to stop pouring alcohol down the throat of a patron who, because of alcohol, has lost control over his judgment, his reflexes, and his sense of responsibility to others," Williams said.

Some state judges in Virginia have rejected Williams' ruling. Fairfax County Circuit Court Judges Thomas A. Fortkort and Jack B. Stevens have dismissed two dramshop cases in their county. Stevens said the legislature -- not the courts -- can impose liability upon tavern owners.

Justice Department lawyers, citing the rulings by the two state judges, have filed a motion for Williams to reconsider his ruling.