Cripple Mr Onion was originally a fictional card game played by characters in Wyrd Sisters, Reaper Man, Witches Abroad, Men At Arms, Wintersmith and Lords and Ladies. A game called "Shibo Yancong-San" appears in Interesting Times also. This was used by Dr Andrew Millard and Prof. Terry Tao as the basis for an actual card game. The complete rules and design of this game were posted on USENET around 1993. It contains elements of blackjack and poker.
The rules as posted on USENET were approved by Pratchett himself.
The most notable aspect of the game is that it requires an eight-suited card deck. The game divides the eight suits into pairs: spades and axes, clubs and tridents, hearts and roses, diamonds and doves. Two "normal" decks may be used, providing there is some way of distinguishing the "modifier" cards. (These represent the eight Minor Arcana suits of a Discworld "Caroc" deck: staves, swords, cups, coins, octagrams, elephants, terrapins and crowns).
How to play
Each player receives a hand of ten cards: five cards are dealt face-down to each player, and the player may then discard up to four of them, receiving new cards to replace them. Then a further five cards are dealt face-up to each player except the dealer, who receives his face-down. The first player begins by assembling his or her cards into one of the winning groupings described below, and displaying them. The next player must then create a more valuable grouping or fold. If the player is successful in creating a more valuable grouping, the original first player may try again to create an even more valuable grouping for himself, or fold. This process passes left around the table until only one player remains, who then wins the hand.
The categories of winning group, in ascending order of value, are as follows. Number cards are worth their face value, picture cards are worth ten, and aces are worth one or eleven at the player's choice (a la Blackjack).
- Bagel, two cards with values totalling 20;
- Two-card Onion, two cards with values totalling 21;
- Broken Flush, a set of three or more cards totalling between 16 and 21 inclusive, and with all but one in the same suit-pair;
- Three-card Onion, three cards with values totalling 21;
- Flush, as a broken flush but with all the cards being in the same suit-pair;
- Four-card Onion, as two- and three-card Onion above;
- Broken Royal, the combination 678 of any suit;
- Five-card Onion;
- Royal, the combination 777 of any suit;
- Six-card Onion;
- Wild Royal, the combination 888 in a hand when eights are wild (see below);
- Seven-card Onion;
- Double Onion, two picture cards and two aces;
- Triple Onion, three picture cards and three aces;
- Lesser Onion, four picture cards and four aces;
- Great Onion, five picture cards and five aces.
"Modifiers" may also be played to increase the value of a hand. Apart from the crippling rule, modifiers are optional rules, which may or may not be included in a game. The available modifiers (many of which are named after Discworld characters or concepts) are as follows:
- Crippling Mr Onion: if a player displays a Great Onion, an opponent may display a nine-card running flush and instantly win the hand. If a player displays a Great or Lesser Onion, an opponent may display a ten-card running flush and instantly win the hand; a player with a ten-card running flush can also use it to steal the win from someone who has previously crippled Mr Onion with a nine-card running flush. (This is the only non-optional modifier.)
- Null Eights: in a normal hand, eights may be played as if their value were zero (but can be still be played with value eight if the player wishes). Thus they can be included in an existing Onion in order to improve its size by one card. Whenever this is done, eights become wild cards in the following hand, and this modifier cannot be used in that hand. After one hand with eights as wild cards, they revert to normal, and this modifier becomes available again.
- Wild Crippling: when eights are wild, you cannot Cripple Mr Onion if your running flush contains more wild eights than the Lesser or Great Onion you are trying to cripple.
- Octavo: when eights are wild, the grouping 88888888 is considered a Lesser Onion, but beats any other Lesser Onion and is considered a Great Onion for the purpose of being crippled.
- The Lady: a player may reveal the Queen of Spades for one of two effects: if eights are not wild in the hand, the player may draw two cards from the deck, then choose one of these cards to replace the queen in their hand. If eights are wild, the player can force every opponent to devalue one ace in their hand to value 1 (rather than 11). The opponent chooses which ace is devalued.
- Fate: if the Lady has been played and replaced with another card from the deck as above, the King of Cups may be revealed and replaced in the same way, also rendering all Aces held by the player who played the Lady unplayable. If eights are wild, the King of Cups may be played to immediately cause them to cease being wild; but if played this way, any other (not the same!) player who holds the Queen of Spades may reveal it to cause their eights to remain wild.
- Great A'Tuin: a player who reveals the Queen of Coins may subtract eight from the value of one of their cards and add it to the value of another. Card values must still range from 1 to 11.
- The Elephants: a player who reveals a set of four cards, each either a nine or ten (or a wild eight), plus the Queen of Coins, may shift points of value between their cards to create a Double Onion, and may consider any other nines or tens in their hands as ones (not aces) and twos respectively. However, any other Double Onion beats this one.
- The Sender of Eights: displaying a Jack of Diamonds when eights are not wild causes the aces of any other player who has used a Null Eight to become unplayable. When eights are wild, displaying a Jack of Diamonds makes all aces unplayable and bans wild eights from taking value 1 or 11.
- Death: displaying a King of Swords "kills" one picture card in the hand of every player who has more than one in their hand. A "killed" picture card may not participate in a Double Onion, and if eights are wild may not participate in a Triple Onion either, but may still participate in other groupings.
- The Archchancellor: When played, the Jack of Staves is wild in all hands. However, any player who plays a Jack of Staves must play all their eights as null eights. Further, any opponent may reveal a King of Swords after the Jack of Staves is revealed to cause the Jack of Staves to cease being wild and also cause all other players to reveal a card they have not yet revealed.
- The Fool: If the Jack of Clubs is declared by any player before the first player has played their first group of cards, Bagels and Onions switch places in score value. Thus, Double Bagels, Triple Bagels, etc. become the most valuable hands, with the exception that a Great Onion will still beat a Great Bagel. It also, of course, becomes possible for a player to Cripple Mr Bagel.
- The band "Cripple Mr Onion", a Progressive metal band, originally from Christchurch, New Zealand, was named after the game.
- Cripple Mr Onion Full Rules
- List of games with concealed rules