Liar's dice

Liar's dice (liar dice) is a dice game for two or more players. It is easy to learn, requires minimal equipment, and can be played as a gambling or drinking game. Playing this game well requires the ability to deceive and to detect an opponent's deception. Liar's dice is known as Perudo in South America and a version under this name is commercially available in the UK. The game has also been marketed under the name, Call My Bluff.

Rules

Five six-sided dice per player are generally used for play. Generally play includes dice cups for concealment as well.

Each round, the players roll their dice, keeping them concealed from the other players. One player begins bidding, picking a number 2 through 6. He then tenders a number which he guesses to be less than the cardinality of the set of dice displaying this number on their top surface.

For example, the player might bid "three 4s". For the purposes of bidding, a 1 is wild and can count for any number 2 through 6.

After the first player has made his or her bid, the next player to the left can raise the bid or challenge the previous bid. Raising the bid means either raising the number chosen, or raising the quantity, in which case any number is allowed.

In the above example, the bid is "three 4s". The next player could bid "three 5s" or "four 2s", but not "three 2s" or "two 6s".

A player may challenge a bid. In some variants the player may only challenge when it is his turn to bid, in other variants the player may challenge at any time.

A challenge is generally indicated by revealing one's dice. All players then reveal their dice as well. The number chosen as well as the quantity is compared to the cardinality of the set of dice showing the number on their upper face. Most common variants also add 1s showing to this set for calculation purposes. A challenge is judged to be successful when the quantity guessed is greater than the cardinality of the set. A challenge is deemed to have failed if the quantity guessed is equal to or less than the cardinality of the set.

For example, if the bid of "seven 2s" is challenged, the quantity of 2s is counted. Say there are five 2s and three 1s showing; this is a total of eight 2s (assuming that a variant is played where 1 is wild). There are seven or more 2s, so the challenging player loses the challenge. If there are instead five 2s and only one 1, there are only six 2s and the bidding player loses the challenge.

Variants

• A player that loses a challenge loses a die, and the next round begins. If there are three players and on the first round, Player 1 loses a die, then in the second round Player 1 has only four dice, whereas Players 2 and 3 still have five. This puts Player 1 at a disadvantage as he has less information than the other players about the dice.

• It is possible to call 1. For example, "Three 1s". In such a bid, there are no wild dice. When switching the bid to 1, the bid must respect the minimum of previous bid, divided by 2, rounded up. To switch back, respect the minimum of previous bid, multiplied by 2, plus 1. For example, a bid of four 6s could be followed by a bid of two 1s, which could in turn be followed by three 1s or five of any number.

• 6 is wild instead of 1

• When one player has distinct dice, he can pass once. If he does so, the bid raises automatically, and the next player cannot challenge the bid. Next player can raise using standard rules, challenge the passed status or pass as well. If more than one player pass simultaneously, next player's pass challenge can target any of them.

• Instead of raising or calling ('dudo'), the player can bet that the bid from the previous player is exactly correct. If the number is higher or lower, they loose a die, however if they are correct, they get to gain a discarded die.

Gambling

There are a number of different ways to gamble with liar's dice. The simplest and probably most popular is for each game to be winner take all.

Drinking Game

A few possible alternatives exist here

• A successful challenge leads to the last bidder before the challenge to drink.

• Sometimes the drinking above is based upon the difference between the quantity guessed and the set of dice used in comparison.

• A failed challenge requires the challenger to drink.

• A failed challenge requires the challenger to drink in a much greater quantity if it were not the turn of the challenger to bid at the time of challenge.