A 2009 memorial to River Hill's football player Steven Joseph Dankos, 17, killed in a drunk driving crash that figured into a major Maryland Court of Appeals opinion Tuesday. (Marvin Joseph/The Washington Post)

Adults who provide alcohol to underage drinkers can be held civilly liable for any death or harm that comes to others at the hands of the young people they hosted, according to an opinion Maryland’s highest court issued Tuesday.

The opinion sets a legal precedent in Maryland and comes after the state’s General Assembly grappled with how to toughen criminal penalties for adults who host underage drinking parties.

The ruling from the Maryland Court of Appeals holds that adults should be responsible for the actions of the underage drinkers they host because those under 21 aren’t competent to handle the potentially dangerous effects of alcohol.

“Children under 21 are often less able to make responsible decisions regarding the consumption of alcohol and, as a result, are more susceptible to harming themselves or others when presented with the opportunity to drink in excess in a social, peer-pressured setting,” the court wrote. . “The adult increases the risk of harm to themselves and others by facilitating the improper conduct of another.”

According to the decision, Tuesday marks the first time the Court of Appeals has recognized in Maryland law what is known as “social host liability” — a term that refers to those who negligently serve alcohol and are then subject to the consequences. The adult must “knowingly” and “willfully” furnish the alcohol to someone under 21 in order to be held culpable, the court ruled.

The appeals ruling stems from two cases. In Manal Kiriakos v. Brandon Phillips, the court said that Kiriakos was walking her dog when an 18-year-old struck her with an SUV in 2011. The teen had been drinking at Phillips’s home in Baltimore County and Phillips had been mixing drinks, the court stated. Kiriakos sued, saying Phillips should not have provided alcohol to someone underage who would later drive under the influence.

In Nancy Dankos, et al. v. Linda Stapf, the court said that Dankos’s 17-year-old son got drunk in the garage of Stapf’s Howard County home in 2009 and got in the bed of a pickup truck with an intoxicated partygoer at the wheel. The truck — full of current and former football players from River Hill High School — crashed, killing Dankos. Dankos sued Stapf, saying she was responsible for the death for allowing the teen to get so intoxicated he couldn’t make a smart decision getting in the truck.

“This is a wake-up call to the so-called cool parents who on Friday nights have their kids’ friends over and allow them to drink in their basements,” said Tim Maloney, the attorney representing Dankos. “This has been an epidemic in some communities when these kids go out and get behind the wheel and someone pays the price.”

The Court of Appeals opinion returns the cases to circuit courts in Howard and Baltimore counties for new proceedings on the lawsuits.

This spring, the Maryland legislature passed a bill that stiffens fines and jail time for adults who provide alcohol to underage drinkers. The bill was named for Alex Murk and Calvin Li, two 18-year-olds from Montgomery County who died in a car crash after an underage drinking party where a teen’s father was in the house.