The college student game of "Assassin" isn't so much fun in the wake of deadly campus shootings, and University of Nebraska-Lincoln officials have banned it from the campus.

The game had turned dangerous Wednesday when university police were called to an Oldfather Hall classroom by the report of a masked gunman. Officers arrived within two minutes and found a student in a ski mask, armed with a toy gun that shoots foam darts.

He was a player in the game sponsored by Neihardt Residence Center, a coed dormitory. The game is commonly called by its old name "Assassin," but is now called "Live Free or Neihardt."

Smith Hall has its version of the game and calls it "Cupid's Rampage," said student Erin Wesely, who lives at the dorm.

In "Assassin," each player gets another's name as his or her target. The players then try to "assassinate" their targets by hitting them below the head with foam darts or paperclip "bullets" or some other benign projectile.

In some version of the game, water pistols are used. At Bowdoin College in Brunswick, Maine, the would-be assassins used socks.

The "killer" get the vanquished target's target and continue his or her bloodless trail to the final showdown against another player. In some games, the winner claims a pot of money.

The Nebraska university worries that a harmless game could turn deadly.

"We want to make sure we don't have students running around campus with guns, even if they're plastic," said the vice chancellor for student affairs, Juan Franco.

In an e-mail sent to students Wednesday, Franco said the game was "extremely inappropriate in this day and age in which we are all too familiar with the Virginia Tech and Northern Illinois University shootings."

"At this time, this game is at least disruptive, and could be dangerous if anyone misinterpreted a toy gun to be real," he said.

In April, a gunman killed 32 people at Virginia Tech in Blacksburg, Va., before turning a gun on himself. Earlier this month at Northern Illinois in DeKalb, a gunman fatally wounded five students before killing himself.

In the wake of those tragedies, college officials across the nation are taking few, if any, chances.

A report Thursday morning of a man carrying an assault rifle prompted police to shut down California State University, Dominguez Hills. A search of the sprawling Carson campus soon turned up an ROTC student who was practicing with a fake rifle.

On Wednesday, officials at St. Peter's College in Jersey City, N.J., locked down the campus for several hours after a note referring to the Virginia Tech and Northern Illinois shootings was found on a wall in a campus building. A room-by-room search found nothing dangerous.

UNL Vice chancellor Franco said he hasn't received any complaints yet about the decision to ban the games.

"We did talk to some students even last night and they understood," he said. "Obviously, they were just doing it for fun."

Violators of the ban could end up being disciplined, but he doesn't expect students to press the issue that far.

The ban includes the entire campus, including dorms and sanctioned fraternity and sorority houses.