Four By 21

Four columns. One goal: 21.

Four By 21 is a fast-paced card puzzle where blackjack strategy meets solitaire. Stack cards into four columns, make 21, clear space, and race the clock.

Use HOLD wisely, build streaks, and chase high scores without busting.

How to Play

- Place Your Cards: Tap one of the four columns to place your active card.
- Reach 21: Make a column total exactly 21 to clear it and score points. Aces count as 1 or 11, and face cards count as 10.
- Watch the Busts: If a column goes over 21, you bust. You only get 5 busts per round before it is game over.
- Beat the Clock: You start with 70 seconds. Every time you clear a column, you earn bonus time to keep the game alive.

Key Features and Scoring Strategies

- The Hold Slot: Tap the Hold zone to save your active card for later. Swap it out when the right moment arrives to save a column or score a combo.
- Streak Multipliers: Chain together rapid clears without mistakes to build your streak multiplier and drive up your score.
- 5-Card Charlie: Play five cards in a single column without busting to clear it instantly for a 600-point reward.
- Lucky 7-7-7: Stack three 7s to hit 21 and earn a 400-point bonus.
- Board Clear Bonus: Clear all four columns to sweep the board and trigger a big score boost.