Codenames is a popular board game that involves two teams and a grid of words. Each team has a spymaster who gives clues in order to help their team guess the correct words on the grid. The spymaster gives a one-word clue and a number, which represents how many words on the grid relate to the clue. The teammates then discuss and try to guess the correct words based on the clue given. The game continues until one team has correctly identified all of their words or until a team selects the assassin word, which immediately ends the game.