Stack Duel
Tap to drop the sliding block. First tower to the tape wins the point. First to 3.
Stack Duel is a two-player tower-building race in which you tap to drop a sliding block onto your stack. Any overhang is sliced off, so the tower narrows with every miss, and the first tower to reach the tape wins the point.
One tap drops your sliding block; anything hanging over is sliced off and the next block is thinner. Both towers grow towards the middle of the phone, so you watch your rival closing in on the same tape.
Also known as Tower stacking game, Block stacking game.
- How you hold it
- Face-off
- Match
- First to 3
- Length
- About 1 minute
- Play
- Friend or bot
How to play Stack Duel: quick rules
About 1 minute at first to 3. Full rules, options and bot levels are further down.
- 1Tap anywhere on your side to drop the sliding block.
- 2Anything hanging over is sliced off. Land it dead centre for a Perfect.
- 3First tower to the tape wins the point.
Stack Duel rules
Setup
- Each player builds in their own half, from a wooden plinth near their edge towards a finish tape near the middle.
- Both halves are identical, and the number of floors to the tape (10 by default) is the same on every phone.
- Both players start at GO; there is no first move.
Dropping blocks
- A block slides back and forth above your tower. Tap to drop it.
- Slice: whatever overlaps the block below stays; the overhang is sliced off and falls away. Your next block is only as wide as what was kept.
- Perfect: drop it almost exactly on top and it snaps into place at full width. Perfects in a row build a streak.
- Miss: drop it with no overlap and the whole block falls. That floor isn't built and a new block of the same width comes. There's no game over; you just lose time.
- Blocks slide a little faster the higher the tower gets, the same for both players.
Scoring
- The first tower to reach the tape wins the point. Your taps stop counting once your tower is topped.
- Between points both towers are cleared and the race starts again from empty plinths.
Ties and replays
- If both towers are topped at almost exactly the same instant, it's "Too close!" and the point is replayed with no score.
- If nobody finishes within 90 seconds, the point is replayed with no score.
- If three points in a row are replayed this way, the third is settled by a coin toss.
- Pausing or leaving mid-point cancels it; it restarts from empty plinths with the score unchanged.
Winning
- First to the target wins: 2, 3 or 5 points.
Tips to win at Stack Duel
- 1Watch your own block, not your rival's tower: one clean drop beats two rushed ones.
- 2Tap as the block reaches the middle of the one below, not once it's already past it.
- 3Chase Perfects. They keep your block at full width, and with Perfect regrow on every third in a row widens it again.
- 4Every slice makes all your later blocks thinner, so a careful drop early saves time on every floor after it.
- 5Blocks slide faster the higher you build, so stay calm on the last few floors.
Controls
Phone flat between you. Each player owns a half, and the far half faces the far player.
- Your whole half is the drop button, apart from a thin band at the middle line.
- Every touch-down drops a block, even while a new one is just appearing, so no tap is lost.
- Mashing drops blocks badly and slows you down.
- A finger resting on the screen isn't a drop until it lifts and touches again.
Options
Every option is free. Defaults are marked.
| Option | Choices | What it does |
|---|---|---|
| First to | 23 (default)5 | The score that wins the match. |
| Floors | 810 (default)12 | Fewer floors means taller blocks and a shorter race; more means thinner blocks and a longer one. |
| Perfect regrow (extra) | On (default)Off | Every third Perfect in a row widens your block a little, never past its starting width. |
| Rush (extra) | OnOff (default) | A Perfect makes your rival's next block slide faster. |
| Wind (extra) | OnOff (default) | One gust per point over the same three floors for both towers; the block speeds up and slows down. |
Play Stack Duel against the bot
The bot builds Blue's tower. It sees only its own sliding block and the block below, never your tower, and it waits a human-like moment before each drop.
Easy
Aims loosely, waits a while before dropping and sometimes taps at a random moment.
Normal
Aims fairly well and drops at a steady pace, with the odd slice.
Hard
Lands close to centre most of the time and keeps a quick rhythm. Steady Perfects can still beat it.
Online, tournaments and hints
- Online
- One phone onlyBoth players race at the same time and every drop is a matter of timing, so Stack Duel stays on one phone.
- Tournament
- Can be drawn in a tournamentIn a tournament it is always first to 3 with 10 floors and Perfect regrow on.
- Hints
- No hints here: it's all about your own reactions.
How it feels
- A clack on every drop, a snap as the overhang breaks off and a chime that rises with each Perfect in a streak.
- Sliced pieces tumble towards their owner's edge.
- The tape snaps and confetti bursts when a tower tops out.
- Haptics follow your phone's settings and the in-app vibration switch.
Accessibility
- Progress reads from the height of each tower against the tape, and Perfects and misses show words, not only flashes.
- One tap anywhere in your half: easy to play one-handed.
- With reduced motion on, pieces fade instead of tumbling and there is no confetti.
- Scores are announced to a screen reader; the play itself is visual timing.
Stack Duel questions
Tap to drop the sliding block onto your tower; any part hanging over the block below is sliced off. The first player whose tower reaches the tape wins the point, and first to 3 points wins.
A drop that lands almost exactly on the block below. It snaps into place at full width, and Perfects in a row build a streak.
The whole block falls and that floor isn't built. A new block of the same width comes, so a miss costs you time, not the match.
If both towers are topped at almost the same instant, it's "Too close!" and the point is replayed. A match never ends drawn.
Yes. Stack Duel in Duo Clash is built for two players on the same phone. Phone flat between you. Each player owns a half, and the far half faces the far player.
Yes. The bot builds Blue's tower. Choose Easy, Normal or Hard.
Play Stack Duel on one phone
Free on Android. Sit face to face, or take on the bot on Easy, Normal or Hard.
