The game board contains a grid of 24 cards with one word each.
Hidden under each card is the allegiance of the word, either Red, Blue, Decoy, or The Assassin.
Each team elects a Spy Master who is able to see the allegiances of all the words.
Taking turns, each Spy Master gives a one word clue and a number to the rest of the team.
The clue should allow the spymaster's teammates to guess which unrevealed words belong to the team, and the number tells the team how many words the clue relates to.
The Spy Master's team reveals 0 or more cards that they think are part of their team. If the team reveals an opponents card, their turn passes to the other team automatically. Otherwise, they may pass their turn to the opposing team whenever they are done guessing.
The game ends when all of a team's words have been revealed, regardless of who revealed them.
Or
If a team reveals the Assassin card, the other team wins automatically!