Two teams compete by each having a Spymaster give one word clues which can point to multiple words on the board. The other players on the team attempt to guess their team's words while avoiding the words of the other team. If the Assassin card is discovered, the game ends and the team that discovered the card lose. The first team to find all of their agents win.
Several expansion packs have been added since the game's first release including Deep Undercover and Marvel.