"Assassin (also Killer or Paranoia) is a live-action game. Players try to eliminate each other from the game using mock weapons in an effort to become the last surviving player.
Assassin is particularly popular on college campuses; several universities have a dedicated "Assassins' Guild" society, which organizes games for their members. Game play occurs at all hours and in all places unless otherwise disallowed by the rules. Since an elimination attempt could occur at any time, successful players are obliged to develop a healthy degree of watchful paranoia."
Source: Wikipedia, "Assassin (game)", available under the CC-BY-SA License.