In 21+3 Blackjack you try to beat the Dealer by accumulating a card value total close to, but not over, 21 points. You can also make a 3 Card side bet which pays relative to the combination of your first two cards and the Dealer's up card. The Wizard of Odds

Blackjack is a comparing card game between a player and dealer, meaning players compete against the dealer but not against other players. It is played with one or more decks of 52 cards. The objective of the game is to beat the dealer in one of the following ways: Get 21 points on the player's first two cards (called a "blackjack" or "natural"), without a dealer blackjack; Reach a final score higher than the dealer without exceeding 21; or Let the dealer draw additional cards until his or her hand exceeds 21. Wikipedia

Craps is a dice game in which the players make wagers on the outcome of the roll, or a series of rolls, of a pair of dice. Players may wager money against each other (playing "street craps", also known as "shooting dice" or "rolling dice") or a bank (playing "casino craps", also known as "table craps", or often just "craps"). Wikipedia