CONCORD, N.H. — The parents of an elite prep school student who says she was sexually assaulted as part of a game of sexual conquest are suing the school.

St. Paul’s School fostered and condoned a tradition known as Senior Salute, in which upperclassmen kept score of how many younger students they had sex with, said attorney Steven J. Kelly, lead counsel for the girl’s parents.

In a complaint filed Wednesday, the parents say the school “failed in its most basic obligation to protect the children entrusted to its care” including taking action against the predatory behavior of an older student the 15-year-old freshman girl said raped her.

The older student, Owen Labrie, of Tunbridge, Vermont, was convicted last year of misdemeanor sex assault charges and a felony charge of using a computer to lure an underage student for sex, but he was cleared of rape. He was sentenced to a year in jail but is out on bail pending appeal.

Kelly said school officials “knew about the Senior Salute.”

“They knew about games of conquests, a lot of these crazy things that were going on,” Kelly said. “They did nothing to stop it.”

The lawsuit, which alleges negligence and intentional infliction of emotional distress, also accuses the school of failing to support the girl. It describes how she was “shunned, ignored and outright mocked” by the school community. It seeks unspecified damages.

Kelly said the girl’s parents want reforms at the Concord school to ensure the abuse doesn’t happen to other students.

St. Paul’s, a private, Episcopal coed school for students in grades 9 through 12, denied the parents’ allegations.

“We believe this lawsuit is without merit, and we plan to vigorously defend ourselves,” the school said in a statement. “We categorically reject any allegations that St. Paul’s School has an unhealthy culture. The safety of our students has been and will continue to be the highest priority for our school.”

Labrie, who’s 20 years old, was 18 when he was arrested in 2014 days after graduating from St. Paul’s.