Contract which ensures that a game enforces some aspect of waging money.
GamblingPlayer interface
Contract which ensures that a player has some ability to wage money.
The utilities.Console class should NOT be modified. It should be wrapped or encapsulated by other classes.
Developmental Notes
io.zipcoder.casino.CardGames.GoFish.GoFish is a friendly game and should not involve gambling.
BlackJack and io.zipcoder.casino.CardGames.GoFish.GoFish are both card games and should therefore inherit from a common io.zipcoder.casino.CardGames.UtilitiesCards.CardGame.
Any common logic or fields between the games should live io.zipcoder.casino.CardGames.UtilitiesCards.CardGame class, not BlackJack nor io.zipcoder.casino.CardGames.GoFish.GoFish.
You must have a completed and approved UML diagram before you proceed to do any development