Cal's BS

This variation of I Doubt It was developed by Calvin Yoshitake in 1975 and contributed by his son Aaron Yoshitake The author wrote: "This is an extremely fun, lot of laughing, fast, and easy game to learn. It takes more psychology and strategy to win than luck. Game has 5 basic rules and 4 other rules. One hand lasts 4-10 minutes."

Number of Players: 3 to 7, aged 5 to 100

Cards: one standard deck of 52 cards plus 2 jokers (jokers are wild).

  • Deal out all the cards to the players (It may not come out exactly even. That’s OK).
  • Object of the game: the winner is the first one who gets rid of all his cards.
  • The player to the left of the dealer goes first (i.e. is the first lead player).

  1. The lead player must place 1-6 cards face down, in a pile in the center. He declares the true number of cards placed and declares the rank that he claims the cards to be - for example "4 sevens", "1 jack", "6 kings". (The wild jokers make it possible to play up to six cards of a rank.)
  2. The other players play in no particular order. Any other player can:
    1. Pass
    2. Place 1-6 cards face down, on top of the pile, declare the true number of cards played and declare the same rank of card as was previously played.
    3. Doubt the last played set of cards.

    If the cards are doubted, the one who is wrong takes the entire pile and the one who is right becomes the new lead player.

  3. Step 2 is repeated until the pile is taken and the player who is right repeats step 1.
  4. A player cannot place card(s) directly on top of his last placed set of cards unless all the others pass. If all other players pass, then the last player who placed cards becomes the lead player, goes back to step 1 and may change the rank of cards played.
  5. The winner is the player who goes out (gets rid of all his cards). He does this by turning his last cards face up - they must be the correct rank. The lead player can go out with any rank of cards, provided that all his cards are the same rank.

Other rules:

  • If there is a pause in the play - perhaps with everyone waiting to see whether someone else will doubt the last play - the player who was the last to place cards can ask if everyone wants to pass. If there is no response, this player can assume that all have passed, take over the role of lead player and play 1-6 cards of a new rank.
  • Anyone found lying about the number of cards played has committed a great offence and faces public humiliation as agreed upon the other players.
  • When there are no cards in the pile, the lead player may place one or more sets of 4 of a kind onto the pile and declare "all fours", without mentioning the rank. When you say "all fours" you cannot lie and cannot include jokers (on pain of public humiliation, etc. if discovered). The "all fours" rule is used simply to make the game quicker, and should not be used to get rid of spare cards. Other players may put a card on top of the pile, saying "plus one" - this card is claimed to be a joker, since all cards of the "all fours" ranks are already in the pile - and this may be doubted in the usual way.
  • The lead player can declare "going out" if he has 8 or fewer cards and wishes to put restrictions on the next play. As usual, other players can pass, follow rank, or doubt. If a player follows rank, no other player may doubt the last play, except for the player who declared "going out". This allows the person "going out" a fair chance to get rid of all his cards without losing the lead, but also announces this intention to the other players, who may try to prevent him from going out by doubting.
  • Expert players can give a handicap of 2-4 second delay before they can doubt another player.


  • Be quick.
  • Bluff 40-60% of the time.
  • Doubt 10-30% of the time.
  • Try to control the end play.
  • Bluff in the beginning and tell the truth at the end. Once the other players figure it out, mix it up.
  • Don’t break up your 4 of a kind, but put them in a separate pile next to you. This allows you to hold and see your other cards. 4 of a kind are easy to get rid of.
  • Set up your play in going out and look for players going out.
  • Save your jokers for "going out" or stopping someone else from "going out".
  • If you bluff, bluff all the way. Do not tell half-truths. If someone doubts you, you will still take the pile. Save your truths for the next play.
  • Look for other players' tells (subconscious signs that they are lying). Tells can include nervousness, changes in voice, avoiding eye contact, smiling, or quick plays.
  • Keeping your hand sorted makes it easier to see when you can play, and what cards you want to get rid of. Try sorting your hand into "garbage" (cards that you don't have any duplicates of; i.e. singletons) and everything else. Put your fours of a kind on the table, and just get rid of them whenever you want.
  • Big tip: Don't lie by claiming to have more cards of a rank than you actually do, if you're leading. You don't want to be caught saying "three tens" when someone else has two tens.
  • A common trick is to play "three fives," as an example, wait for others to play on top of you, and again play "three more fives." Either of these plays could be a lie, although it's easier to bluff people before they focus on you when you say "three more fives." Notice that if you actually have three fives, no one will know if you're lying unless they flip your cards.


  • Instead of a 52-card pack with two jokers, use a 54-card pack without pictures, made up of 5 cards of each rank from Ace to 10 plus 4 jokers.
  • In rule 2b, increase the number of cards that can be played from 6 to 9 (since it is possible for a 9-card play to be genuine, consisting of 5 equal cards plus 4 jokers).
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Last updated: 28th June 2018