Balderdash is a proprietary board game combining elements of bluff and knowledge of trivia. It is very similar to Fictionary.

The game begins by all players rolling a die, the high roll chosen to be the first "dasher". The dasher draws a "definition card" from the supplied box, and rolls the die to decide which of the five words listed there shall be used (if a six is rolled, the dasher may choose for themselves which word to use. They then write down the real definition of the word (as supplied on the card) on a piece of paper. All other players then write down a definition, which may be an honest attempt to supply the correct definition, or, if they do not know or for tactical reasons decide not to, an imagined definition for the word designed to sound convincing as possible to other players.

The players hand their definitions to the dasher, who checks if any definitions are the same as the real definition. If there are, the player(s) submitting the correct definition is immediately awarded three points, and if there is more than one the round is abandoned (though the points are retained). The definitions, including the real definition, are then read out in random order. Players record which of the answers they believe is correct.

Players are awarded two points if they guess the correct definition, and one point for each player who incorrectly choose the fake definition they wrote. If nobody guesses the correct definition, the dasher is awarded three points.

For each point awarded, players move their tokens around the game board one square. The game continues, with players taking turns to be the dasher. The winner is the individual whose token reaches the end square first.