Get as close to 21 without going over.

Card Values
Aces are 1 or 11, whichever gives the highest score without going over 21.
King, Queen, Jack and 10 are all worth 10. All other cards are worth their rank.

Dealer
Dealer always has one card concealed and one card showing until it is his turn to go.
The dealer always goes second, but must hit on 16 or under and must stay on 17 or over.

Player Actions
Hit: Take another card.
Stand: Take no more cards, also "stick" or "stay".
Double down: Take exactly one more card but double your winnings if you win.
Split: Double the wager and have each card be the first card in a new hand. This option is available only when both cards have the same rank.