Ace of Spades is a very orthodox adult hentai gambling game where you play either Poker or Blackjack against various dealers and then the owner of the establishment herself (who cheats quite a bit).
You, the player, and the adversary, the dealer, each have a stand-in who strips as they are beaten in a game. When you beat the dealer’s stand-in, you face the dealer. When you beat the dealers of each respective game, you face the owner (who uses two stand-ins).
You’ll get CGs for eight women in all (four opponent stand-ins, two dealers, Rina who is your stand-in, and the owner named Serea). To progress and get different scenes, you must win three sets of ten games each (long, but not exceptionally long as Blackjack and Poker aren’t very long games).