Blackjack is a popular card game played in casinos where players try to get cards that add up to 21, or as close to 21 as possible without going over. Each player competes against the dealer, not against each other. Number cards count as their face value, face cards (jacks, queens, kings) count as 10, and aces can count as either 1 or 11, whichever helps your hand more.

Today, getting any ace and any 10-value card as your first two cards is called a blackjack, and it's the best possible hand.

The challenge comes from deciding whether to take another card (called a hit) or keep what you have (called a stand). If you take too many cards and go over 21, you bust and lose automatically. Players must think about probability: with 16, should you risk another card? What if the dealer might have a stronger hand?

The word blackjack can also refer to a small leather-covered club, but that meaning is far less common today than the card game.