Win the duel
Play 1 vs 1 against a campaign rival or a friend sharing your phone. Be first to win three hands through careful hits, timely stands, and clever tactics.
One game. More ways to play.
Challenge a rival, join a five-player table, or share the fun with friends on one phone.
Blackjack-inspired. Built for strategy.
Get closest to 21 without going over. Choose 1 vs 1 or Group Game from the illustrated home screen, with portrait play, animated deals, clear turn indicators, and win, loss, and tie celebrations.
Your five-player table
Group Game seats five players: you and four named computer rivals by default. Play five rounds; the closest total to 21 without busting earns a point. Tied winners each score, and all-bust rounds award no points. Most points wins the match.
Pass the phone
Bring two to five human players to a group table, with computer rivals filling the remaining seats. A private handover screen lets each friend reveal their own hand. Hands stay hidden from other players until the round ends.
Unleash Star Powers
Turn a hand around with powers such as Nova, Twin, Void, Gravity, Orbit, Supernova, North Star, and Comet. Group Game lets you choose three: each is usable once per match, with at most one power per round. In 1 vs 1, up to two powers can be used per match.
Challenge 30 rivals
Climb six leagues against named opponents with increasingly sophisticated strategies and personalities.
Build your loadout
Equip tactics for the campaign and adapt to each rival. Group Game includes Scout to peek at the next card and Swap to exchange a card, each usable once per round. Group points stay separate from campaign diamonds and rankings.
Make it your table
Start with a friendly brown bear portrait, then choose a human or animal portrait—or your own photo—in Profile. Your chosen look follows you through group turns and pass-and-play. Sound and reduced-motion settings let you adjust the experience.
Earn diamonds through play
Progress, daily openings, achievements, and optional rewarded videos provide in-game diamonds with no cash value.
Play offline
Campaign duels, group tables, and pass-and-play work offline, with local saves for returning to unfinished games. Internet access is needed for ads and online services. Card order is never manipulated by opponent difficulty.
Fair play by design
A card game—not gambling.
Card Duel 21 is designed as strategic entertainment. It contains no cash wagering, cash prizes, cash-out system, or paid randomized rewards.
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Campaign play stays freeNormal matches never require spending diamonds.
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Ads between playWhen available, full-screen ads appear after every third completed 1-vs-1 match, or when continuing from group round 3 to round 4. The ad-removal upgrade skips these ads; rewarded videos remain optional.
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No real-money valueDiamonds cannot be sold, transferred, or redeemed outside the game.
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Privacy choices respectedAdvertising consent controls are provided where required.