The rules are otherwise the same as standard blackjack: players can choose to draw an extra card from the top of the deck, or stick on what they have if they feel it’s close enough to 21. You know, like the stuff you don’t remember from your school maths lessons - 6-4X, 24/X and so on. Except these cards can’t exactly be called “standard”, because in place of suits and numbers they have algebraic equations. Like standard blackjack, 21X is played with a single deck of playing cards. What could it possibly be missing? Well, how about algebra?ĭesigner Leo Samson and new card game 21X seems to think that’s the case, introducing a mathematical twist (ha, ha) to the classic game of 21. It’s fast and easy, as players simply choose to twist or stick as they draw cards to get as close to 21 without going over.