D'Alembert System	:	A progressive system of betting whereby two numbers are cancelled every time a previous bet is won and one number-the total of the two end numbers-is added whenever a previous bet is lost.
Deal Button (Video Poker)	:	A button, when pressed, that shows the five new cards constituting an original poker hand.
Dealer	:	The casino employee who staffs and services any of the gambling games the house offers.
Deck	:	The ordinary pack of fifty-two cards consisting of four suits, each suit containing thirteen cards from the 2 to the ace.
Derniere (Roulette)	:	The French term for last, as in a column or dozen bet.
Dice (Craps)	:	A pair of cubes, each with six sides numbered with from 1 to 6 dots, whose combinations, when thrown, determine the wins and losses.
Die	:	A single cube, singular of dice.
Disk (Craps)	:	A round plastic object which is black on one side and white on the other. When on the white side and in a place number, it designates that a shoot is in progress and that that number is the point.
Dollars	:	The insider's term for $100 chips.
Don't Come Bet (Craps)	:	A wager made against the dice after the come out roll.
Don't Come Box (Craps)	:	The area on the craps layout where a don't come bet is made.
Don't Pass Bet (Craps)	:	A bet made on the come-out roll that the dice will lose or won't pass.
Don't Pass Box (Craps)	:	The area on a craps layout where a don't pass bet is made.
Double Down (Blackjack)	:	A player's option to double his original bet by turning over his first two cards and placing an amount equal to the original bet on the layout.
Double Odds (Craps)	:	A free odds bet made at double the original bet on a line, come, or don't come wager
Double Zero (Roulette)	:	See Zero
Douzaine (Roulette)	:	The French term for the dozen bet.
Dozen Bet (Roulette)	:	A wager on either the first, second, or third dozen on the layout, such as 1-12, 13-24, and 25-36.
Draw	:	Keno-The movement of a numbered Ping-Pong ball into the goose, forced there by hot air from the blower.Video Poker-To receive new cards, up to five, after the initial poker hand has been dealt.
Draw A Card	:	The taking of an additional card by a player in either baccarat or blackjack.
Draw Button (Video Poker)	:	The button, when pressed, that allows the player to draw up to five new cards to his original poker hand.
Draw Ticket (Keno)	:	See Punch-Outs
Drop	:	The casino term for the total money and markers wagered on its table games, from the term "drop box," which is a container where all cash winds up. Drop boxes are located within the interior of the craps, blackjack, and other gaming tables.
Duplicate, Duplicate Ticket (Keno)	:	The ticket marked by the keno writer and returned to the player, duplicating the original ticket.