A Blackjack, or natural, is a total of 21 in your first
two cards. A Blackjack is therefore an Ace and any ten-valued
card, with the additional requirement that these be your
first two cards. If you split a pair of Aces for example,
and then draw a ten-valued card on one of the Aces, this
is not a Blackjack, but rather a total of 21. The distinction
is important, because a winning Blackjack pays the player
odds of 3 to 2. A bet of $10 wins $15 if the player makes
a Blackjack. A player Blackjack beats any dealer total
other than a dealer's Blackjack, including a dealer's
regular 21. If both a player and the dealer make Blackjack,
the hand is a tie or push.
The dealer will usually pay your winning Blackjack bet
immediately when it is your turn to play. In the face
down games, this means that you should show the Blackjack
to the dealer at that time. Some casinos may postpone
paying the Blackjack until after the hand is over if the
dealer has a 10 card up and has not checked for a dealer
Blackjack. Other casinos check under both 10 and Ace dealer
upcards, and would therefore pay the Blackjack immediately.
Regardless, when you are dealt a Blackjack, turn the cards
face up, and smile. It only happens about once every 21
hands, but it accounts for a lot of the fun of the game.