Free
About
Every column is a stick of dynamite.
Boom 21 is a calm, turn-based card puzzle with an explosive heart. Drop playing cards into
columns and stack them toward exactly 21 - hit it, and the column erupts in gold. Go over,
and it burns. Every card is a decision.
HOW IT PLAYS
Cards fall one at a time from a fairly shuffled deck. Tap a column to place each card. When a
column's total reaches the threshold, its fuse ignites and starts burning down — leave it
alone and it explodes on its own, scoring what it holds. Or take the risk: keep adding cards,
push the total toward a perfect 21, and earn double. But one card too many and the column
busts, costing you a life.
CLIMB THE LEVELS
Fill the progress bar with explosions to raise the threshold: 17+, then 18+, 19+, 20+ — each
level narrows your target and sharpens every choice. Reach the end and face the FINAL 21,
where only perfection counts and every perfect 21 restores a life. How far can you climb?
FAIR BY DESIGN
No timers. No pressure. No rigged draws. Boom 21 deals from an honest 52-card shuffled deck —
the same odds as a real deck of cards, always. See the next cards coming and plan ahead. When
you lose, it's a lesson; when you win, it's yours.
FEATURES
- Calm, turn-based play — think as long as you like
- A fair 52-card shuffled deck, never stacked against you
- Rising threshold levels and the FINAL 21 endgame
- Explosive celebrations: chains, perfect 21s, and level-up confetti
- Your run is saved automatically — pick up right where you left off
- Run history and personal records
- Plays fully offline, anywhere
- Available in 8 languages
- No ads, no account, no data collected
One rule. Endless depth. Make 21 — and boom.
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What's New in Boom 21
1.0
July 9, 2026




