Dudo

Dudo (Spanish for I doubt), also known as Cacho, Pico, Perudo, Liar's Dice, Cachito or Dadinho is a popular dice game played in South America. It is a more specific version of a family of games collectively called Liar's Dice, which has many forms and variants. This game can be played by two or more players and consists of guessing how many dice, placed under cups, there are on the table showing a certain number. The player who loses a round loses one of their dice. The last player to still have dice is the winner.

Game play
Each player starts having five dice and a cup, which is used for shaking the dice and concealing the dice from the other players. Players roll a die in order, to determine where and in what order they sit. Highest first, then next lowest and so on. In the event of a tie between 2 players, they simply re-roll until one gains a higher score.

After deciding who starts the game (this can be done by making each player roll one die, for example), the players shake their dice in their cups, and then each player looks at their own dice, keeping their dice concealed from other players. Then, the first player makes a bid about how many dice of a certain value are showing among all players, at a minimum. Aces (dice showing a one) are wild, meaning that they count as every number. For example, a bid of "five threes" is a claim that between all players, there are at least five dice showing a three or an ace. The player challenges the next player (moving clockwise) to raise the bid or call dudo to end the round.


 * Raise: also known as "bid" in most versions, a player can increase the quantity of dice (e.g. from "five threes" to "six threes") or the die number (e.g. "five threes" to "five sixes") or both. If a player increases the quantity, they can choose any number e.g. a bid may increase from "five threes" to "six twos".
 * Bidding aces: a player who wishes to bid aces can halve the quantity of dice, rounding upwards. For instance, if the current bid is "five threes" then the next player would have to bid at least three aces. If the current bid is aces, the next player can call dudo or increase the quantity (e.g. "four aces") or bid a different number, in which case the lower bound on the quantity is one more than double the previous quantity—for instance, from "three aces", a player wishing to bid fours would have to bid "seven fours" or higher. Players are not allowed to begin a round betting on aces unless the have only one die left.
 * Call: also known as dudo, if the player calls, it means that they do not believe the previous bid was correct. All dice are then shown and, if the guess is not correct, the previous player (the player who made the bid) loses a die. If it is correct, the player who called loses a die. A player with no dice remaining is eliminated from the game. After calling, a new round starts with the player that lost a die making the first bid, or (if that player was eliminated) the player to that player's left.
 * Spot on: also known calzo (etymology: perfect shoe fit) in some versions, the player claims that the previous bidder's bid is exactly right. If the number is higher or lower, the claimant loses a die, otherwise, they recover a lost die. This is a reward for incurring on additional risk. Regardless of the outcome of the spot on, the previous bidder will not lose a die. The spot on can be played for as long as there is more than half of the original number of dice left on the table.
 * Pass: The player decides not to place a bid. A pass is legal if the player has a full house (a pair and three of a kind), five of a kind, or five different suits. Two players cannot pass in a row, and each player can only pass once per round. Passes can be bluffed, and they can also be called out. After a player passes, the next player cannot call the previous bid, and can only call the pass.

When a player first reaches one die (i.e. loses a round and goes from two dice to one), the player obliga (meaning "they coerce") the round. In this kind of special round, aces don't count as wildcards, and the suit can only be changed by players with a single die. The player gets to choose if they play the round open or closed. In an open round, everyone can see everybody's dice but their own. However, in a closed round, only the players with one die remaining can see their dice.

The game ends when only one player has dice remaining; that player is the winner.

Rule variants
Some versions of the game have players lose a number of dice equal to the difference between the challenged bid and the correct number of dice.