On a college campus, a mysterious gunman follows a student around a dormitory and into an alleyway before shooting him in the forehead with a rubber dart. Meanwhile, psychology student Susan Swayze studies a “victim profile” and follows her target into a dormitory laundry room. She and the young man shoot at each other with darts until Susan ducks into the room occupied by Alex Marsh, a reporter for the school newspaper, the Monitor. Instantly attracted to her, Alex watches as she sneaks out the door and back down the hallway. The next day, Alex writes about the encounter for his editor Frank English, announcing his plans to continue investigating the national phenomenon known as “TAG,” or “The Assassination Game,” the dart gun competition played among students on college campuses. Alex then visits the university’s eccentric TAG organizer, Nick Carpenter, and asks about Susan’s whereabouts. Suspecting Alex to be an agent working for another player, Nick refuses to give him Susan’s name. However, while Nick speaks with five-time undefeated TAG champion, music major Loren Gersh, Alex finds Susan’s profile and copies her information in a notepad. Later, a player named Randy Simonetti follows his target, Susan’s roommate, Nancy McCauley, to the women’s locker room and watches her change into her bathing suit. As she swims in the pool, Nancy feigns drowning, forcing Randy to jump in and save her. Once out of the water, she pulls a dart gun from her bathing suit and shoots him. That evening, in the men’s showers, a player’s gun misfires and shoots Gersh in the shoulder. Unable to accept that he has been eliminated from the game, Gersh angrily returns to his dormitory and fills his dart gun with a magazine of real bullets. After turning on all the sinks and showers to cover the noise of the gunshot, Gersh kills his assassin and stuffs his body in a laundry cart. That evening, Alex sneaks into Susan’s dormitory and asks if he can shadow her as research for the article. Meanwhile, Gersh telephones Nick to report his kill, and the organizer believes he is speaking within the terms of the game. Susan gives Alex keys to a convertible, instructing him drive her to the fraternity house of her next target, Richard Chudnow. While parked outside, Susan answers Alex’s personal questions, revealing that she does not believe in relationships and plays TAG because she feels “safe” knowing it is just a game. When she notices Richard approaching, she kisses Alex to distract her target before quickly turning around to shoot him. The next day, Gersh spies on Nancy as she teases Susan about Alex. Nancy also reveals she quit the game because she has started dating Randy. Later, while Nancy watches Randy at track and field practice, Gersh sneaks under the bleachers and shoots her, dragging her body away. Later, Frank tells Alex about two missing student reports, but Alex, engrossed by a stack of psychology books, is only interested in following Susan. In the student affairs office, Alex receives a telephone call from Susan asking him to help her evade her most recent assassin, Wallace, who lurks in the hallway nearby. Alex picks up the intercom and makes an announcement about a free music concert on campus, and the assassin leaves, allowing Susan and Alex to spend the day together. That night, Susan attempts to copy Nancy’s trick by luring Wallace to the swimming pool. While she swims, Alex runs into Gersh, who directs him to Wallace. As Susan pretends to drown, Gersh kills Wallace. Determined to track down Burt Gawdy, her next target, Susan sneaks through the gym after instructing Alex to go to her locker and retrieve extra “ammunition.” Although he forgets the combination, he runs into Gersh again and asks to borrow his gun. Back inside, Alex tosses the weapon to Susan, who shoots Gawdy with a dart. Upon returning the gun, Susan opens Gawdy’s victim profile and realizes that because Gersh is the only other remaining player in the game, she will have to challenge him in the final round, set to take place the following evening. While dropping Susan off at her dormitory, Alex nervously lingers in the doorway, but she does not invite him in. Throughout the next day, Alex has three boxes of roses delivered to Susan’s room. One contains a note confessing his love for her. At the pre-final celebration party that night, Susan avoids Alex and rejects his advances. Hurt, Alex leaves, and Susan returns to her dorm room. At 9:00 pm, Gersh telephones Susan and arranges to meet her on the campus quad. Meanwhile, Alex moodily works in his darkened office, offering to investigate the growing number of missing persons cases while Frank attends a concert with his girl friend. While Alex visits the campus security office, he overhears Randy’s report about Nancy’s disappearance and remembers Nancy as Susan’s roommate. Elsewhere on campus, Gersh locks Susan in a darkened recording studio and loudly plays one of his concertos over the sound system. Before he can reach her however, Susan escapes and wedges a chair under the doorknob, trapping him inside. In Nick’s office, Alex looks at Nick’s kill list and realizes that Gersh “assassinated” all of the supposed missing players. While looking for a hiding place, Susan finds the five victims’ bodies hidden in a laundry closet. Running across the quad, she begs a security officer for help, but Gersh appears and shoots him. Gersh then follows her to a party, where he loses sight of her among the crowd. After looking up Gersh’s information, Alex finds the security officer’s body and steals his gun. Susan locks herself on the roof of a bell tower, but Gersh manages to open the door. Although Susan hits him with a dart, Gersh refuses to forfeit. Hearing the commotion, Alex runs upstairs and shoots Gersh, who tumbles backwards over the ledge to the ground. After watching him fall, Susan and Alex kiss, and Alex tosses her dart gun over his shoulder.