A lot or a little?
Parents need to know that RogueJack: Roguelike BlackJack is a card-based action/adventure game for iOS and Android devices. While you do get into fights with such creatures as goblins, giant spiders, and walking skeletons, the fights are conducted by playing rounds of Blackjack. Also, because the game's graphics are retro and pixelated, there's no blood or gore. Players can watch ads to keep playing when they die, but there's also an ad-free version for $1.99. Read the developer's privacy policy for details on how your (or your kids') information is collected, used, and shared, and any choices you may have in the matter, and note that privacy policies and terms of service frequently change.