Rules
Big Small was the first game of the final in The Devil’s Plan season 2. It is a two-player duel of reading and nerve: one player hides a card, the other bets on whether it beats a card everyone can see.
Setup
Each player has eleven cards numbered 0 to 10 and 10 chips. The dealer has a separate deck for each player, the numbers 1 to 9, shuffled.
A round
- One player is the Contester, the other the Bettor.
- The dealer turns over the top card of the Contester’s dealer deck for both players to see.
- The Contester plays one of their own cards face down.
- The Bettor calls BIG (the Contester’s card is higher than the dealer card) or SMALL (lower), and stakes any number of chips from 0 to everything they have.
- The card is revealed. If it is higher than the dealer card, the Contester takes the difference from the bank. A correct call wins the stake from the bank, a wrong call loses it. If the cards are equal, the stake is refunded.
Played cards are gone. Roles swap every round, so over 18 rounds each player contests 9 times and ends with 2 cards unplayed.
End of the game
After 18 rounds the player with more chips wins. A player who reaches 0 chips loses at once.
Our version
- A seeded coin flip picks the first Contester. Roles then alternate every round.
- Each player’s dealer deck is turned in order on their own Contester rounds, so you meet all nine of your dealer cards in the full game.
- The stake can be any whole number from 0 to all of your chips. The show’s exact limit was not confirmed; 0 to all is our reading.
- Every bet is against the bank: the Contester’s gain and a correct stake are paid by the bank, and a lost stake goes to the bank.
- The Bettor must call a side even when staking 0. A 0 stake simply risks nothing.
- Each decision has 30 seconds. If the Contester runs out of time, their lowest card is played. If the Bettor runs out of time, they stake 0.
- The game ends after the last round, or at once when a player’s chips reach 0. Equal chips at the end is a draw.
- The cards-left tracker (helpers setting, on by default) crosses out every card your opponent has already shown. You could work it out yourself, since all played cards are public.
- Quick mode plays 10 rounds, 5 as Contester each, with the same rules.
Strategy
Count their hand. Every card your opponent plays is revealed, so you always know what they still hold. If none of their cards beats the dealer card, SMALL cannot lose. Bet everything.
Bet in proportion to your edge. If BIG and SMALL are both possible and your opponent mixes well, your edge is small, so stake little. Save the big stakes for rounds where one side is certain or close to it.
Spend high cards on low dealer cards. A 10 on a dealer 2 earns 8 chips. The same 10 on a dealer 8 earns only 2. Keep track of which dealer cards are still to come in your own deck.
Stay unreadable as Contester. If you only ever go BIG when you can, the Bettor will stake heavily on BIG. Mixing in low cards costs you a small gain but turns their bets into coin flips.
The equal card is a shield. Playing a card equal to the dealer card refunds any bet. When the Bettor has a strong read on you, it can be worth more than a small gain.
Mind the bankroll. An all-in bet on a hunch can end the game on the spot. Ahead late, bet small and let your Contester rounds do the work.
Sources: fan analyses of the show.