num. 二十一, 二十一个

n. 二十一, 二十一个, 二十一点牌戏

Vingt et un \Vingt` et` un"\ [F., twenty and one.]
A game at cards, played by two or more persons. The fortune
of each player depends upon obtaining from the dealer such
cards that the sum of their pips, or spots, is twenty-one, or
a number near to it; -- also called {blackjack}, or
{twenty-one}.

Note: There are several variations (such as {Caribbean
blackjack}). In the most common variation played in
casinos, there is one dealer who plays for the house,
and up to seven players. The players and dealer each
receive two cards, the dealer's cards usually being one
face up and one face down. The players each in turn
decide whether they will request additional cards
(``hit''), the objective being to reach a sum of card
values as close as possible to twenty-one, without
exceeding that number. If, on hitting, the player's
total card values exceed 21, he has ``busted'', and
lost his bet. Otherwise, the player wins only if his
total card values exceed those of the dealer. ``picture
cards'' (or ``face cards'', being the jack, queen, and
king) are counted as having a value of ten. The ace may
count as one or eleven, at the player's option. Other
than to hit, there are also other possible actions by
the player, such as to ``double down'' (receive only
one additional card, while doubling the initial bet),
or to ``split'' (if the first two cards have the same
value).
[1913 Webster +PJC]