By Richard Zou

Last updated November 2014

A simple command-line blackjack game for multiple players written in Ruby 1.8.7. The program inplements the core blackjack rules.
On a player's turn, he/she may hit until they go over 21. The program supports splitting and doubling-down.

Type

ruby blackjack.rb

at the command-line. You will be prompted for a number of human players and the starting cash for each person. Follow the instructions on-screen for game play.

• blackjack.rb - The main file to run
• card.rb - Contains a Card class
• hand.rb - Contains a Hand class, a class for a hand of cards
• deck.rb - Contains a Deck class
• player.rb - Contains a Player class, a class for a player in the game
• dealer.rb - Contains a Dealer class. The dealer is a player in the game and inherits from Player
• prompt.rb - Contains command-line printing and prompting utilities
• game.rb - Contains the main Game class and information

The program begins by asking how many players are at the table and starts each player off with $1000. Players may make only integer bets. Players can choose to hit until they go over 21. The dealer must hit on 16 and stay on everything above 17.

Doubling-down is supported and may only occur when the player has two cards and if the player has enough cash. In addition, a player who chooses to double down will exactly double his bet and end his/her turn after receiving one more card.

Splitting may only occur when the player has two cards and a player may split as much as he/she wishes.

If a player has a blackjack and the value of the dealer's cards is less than 21, then the player is paid back 3:2. In this case, the amount of money the player receives is rounded up if it is fractional. If a player has a blackjack and the value of the dealer's cards is 21 after the dealer takes his/her turn, then the player only receives his/her bet back.

If a player's cash reserves reach zero, he/she is removed from the game. When all human players are removed from the game, the game officially ends. Press ctrl-c to stop the game otherwise.

The program has only been tested under Windows 8.1 running Ruby 1.8.7. It should work on other operating systems running the same version of Ruby.