By Damian Yerrick and "Poiman".
Copyright (c) 2002 Damian Yerrick.
Copyright (c) 2002 Wikipedia Contributors.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the writeup entitled "GNU Free Documentation License".
This page courtesy of The Everything Development Company.
Bullshit, also called I Doubt It, is a card game in which each of three to eight players tries to get rid of eir hand by playing cards in sequence and lying if they cannot do that. It has a high ratio of fun to learning curve. It is mostly played by children and thus also mostly known as "BS".
Gameplay
The entire
deck is dealt one card at a time face-down to each player. It is generally considered more important to have every card in play than for each player to start with exactly the same amount. The center of the table will hold a pile of cards played during the game. Play starts with whoever has the two of clubs in their hand and continues in a direction chosen in advance.
On each turn, the player must play the cards he has of a certain rank, one above the rank played by the previous player (twos, then threes, then fours). He selects the cards to play, announces how many he is playing and their rank ("two fours"), and places them facedown in the pile in the center. If he doesn't actually have the cards he needs to play at least one of the correct rank, he is supposed to bluff (lie about it), hence the name of the game.
After each player takes his turn and before the next player has, any of the other players can yell out "BS" to challenge the cards that were just played. In some games, the players agree to either wait before playing their turn so other players can think carefully about challenging, or to rapidly take their turns to put more pressure on challengers. When a player yells out to challenge, they turn over enough cards from the top of the pile to decide if the cards that were just played were legitimate (this should be the number of the cards that the player who just took his turn announced; however, it is generally acceptable to turn over more if cheating as described later is suspected). If it turns out that the player played the amount and rank of cards that he announced, the challenger takes the whole pile that had accumulated in the center. If the player was bluffing and did not put down what he announced, he takes the whole pile.
Depending on how you want to play, either the first player to get rid of all his cards (and not lose any challenge on his final play) is the winner, or the last player with cards remaining is the loser. Since Bullshit is almost never played for money or other stakes, players who don't have cards because they've already won can make a challenge that they intend to lose so they can get cards to continue playing.
Strategy
Calculate ahead which cards you will need for the next few rounds so you can maximize your legitimate plays and bluff away the cards you won't be able to use legitimately.
Call BS on purpose to get cards you'll need in 13, 26, etc. turns.
Form alliances.
Hide your nose.
Cheating
While bluffing is a necessary rule of the game, there are additional ways to cheat that are unacceptable. Why someone would cheat in this game is not obvious, since it is rarely played for money or anything other than fun. Nonetheless, cheating is prevalent in Bullshit. Probably the most common technique is to hide cards from your hand so you don't have to play them. Another is to announce the number of legitimate cards you will play but also slip extra cards below them. If you are challenged and the challenger turns over only the number you announced, it is impossible to detect this cheat. However, challengers rarely turn over only the number you announced. Other techniques can be adopted from those of the game of poker.
History
"bullshit@Everything2.com" by Damian Yerrick in 2002, available at http://everything2.com/?node_id=1280186
"Bullshit: encyclopedia article from Wikipedia" by Poiman in 2002, available at http://www.wikipedia.com/wiki/Bullshit