Block Puzzle

The board, the tray, and when a run ends

The board is 8×8 — 64 squares, each of them either empty or filled. The tray below it deals 3 pieces at a time: a slot you have used stays empty, and the next 3 arrive only once all 3 have been placed.

A run ends when none of the pieces still in your tray can go anywhere on the board. There is no level to clear and nothing to complete — the game is endless, and what it keeps is your score.

The pieces come from a fixed catalogue of 19 shapes, from a single square up to a solid 3×3:

• A single square.
• Bars of 2, 3, 4 and 5 squares, lying down and standing up.
• A solid 2×2 and a solid 3×3.
• The 4 corners of a 2×2 — 3 squares each.
• The 4 corners of a 3×3 — 5 squares each.

The refill is drawn uniformly from those 19 shapes and never looks at your board. No shape is chosen because it would fit, and none because it would not — which is what makes "none of these three fit" an honest ending rather than a staged one.

Controls

Pieces never rotate and never flip. Where a piece goes is the only choice the game gives you. That is deliberate: with rotation, dead ends almost stop happening, and the tension this game is built on goes with them.

• Drag a piece from the tray onto the board. While you carry it, it is drawn snapped to the grid as a real piece lying on the board, not floating under your finger — what is on the screen is what happens when you let go.
• The lift is exactly 1 row, the same for every shape: the bottom edge of the piece sits one row above the square your finger is on, and the piece is centred left to right on that square. One rule to learn, whether you are carrying a single square or a bar of 5.
• Where the piece fits it is drawn with filled faces and an outline; where it does not, with the outline alone — the difference is never left to colour. It never vanishes while you are aiming: it goes only when you carry it right off the board.
• Tap is a full second route, not a fallback: tap a piece to select it, then tap a square, and the piece’s top-left filled square lands there. It is there for anything that cannot drag, such as assistive technology or an external input device.
• Letting go where the piece does not fit does nothing at all. The piece returns to the tray, no sound plays and the board is unchanged, so a misjudged aim costs you nothing.

Clearing rows and columns

The lines you are about to clear light up before you release. While a piece is in your hand, any row or column that this position would fill completely is highlighted along its whole length. Clearing on purpose is the centre of the game, and you cannot aim at something you only find out about after letting go.

The moment the piece lands, every full row and every full column is emptied at once. Rows and columns are read from the same board, so a placement that finishes one of each takes both — and they count together as one clear of 2 lines, not as two separate clears.

Only lines clear. A filled 3×3 block does nothing here: that idea belongs to Sudoku, which is already in this collection, and rows and columns keep the rule short enough to say in one sentence.

The highlight is not an estimate. It is produced by running the real placement and the real clear on a copy of the board, so what lights up in your hand is exactly what happens when you release.

How the score works

Two things earn points, and only two: the squares you put down, and the lines you clear.

• Every square of a placed piece is worth 1 point, so the biggest piece in the catalogue, the solid 3×3, pays 9.
• Clearing n lines with one placement adds 10 × n × (n + 1) / 2 on top of that.
• Your best score is the only score the game keeps. There is no ranking and no sharing, and no clock appears while you play — elapsed time goes to your statistics and nowhere else.

Taking lines together pays more, but the growth stops at quadratic on purpose: a bonus that ran away would turn one lucky placement into the whole game, and the game is meant to be the hundred placements around it. For the same reason there is no combo multiplier for clearing on consecutive turns — that rewards not breaking a chain, which is a more anxious thing to play than reading the board.

Mistakes, Undo, and the help you get

Nothing you do on the board is punished. A placement that does not fit simply does not happen, no move is ever counted against you, and a run ends in one way only: nothing left in your tray fits anywhere.

• Undo is unlimited and free, from the first launch. One step back restores the board, the tray, the score and the run’s line count exactly as they were — a line you cleared comes back with everything else. The history keeps your last 2000 placements.
• Undo does not re-draw your pieces. Step back, place the same piece in the same square, and you get the same result: the refill is fixed in advance, so Undo is a way to think, never a reroll.
• There is no Hint, and that is a decision rather than an omission. The board and all 3 pieces are in plain sight, so there is no hidden information for a hint to uncover — it could only choose your move for you.
• There is no rescue either: no clearing part of the board, no extra piece, no continuing a run that has ended. Undo is for the game in progress — once nothing fits, the ending stands and a new board starts, free.
• Your game is saved as you play. This is a turn-based board, so reopening it gives you the exact position you left. The undo history is not saved, so a resumed game starts its history from there.
• Statistics keep games played, best score, lines cleared and total play time. There is no daily board and no streak: consecutive days are not counted, and nothing in the game asks you back tomorrow.

Tips

• Where you put a piece never changes what it pays: its squares are worth 1 point each wherever they land. The only part of the score you steer is the clear bonus — and a single line already pays 10, more than the biggest piece in the catalogue, which pays 9.
• Take lines together when you can. One placement that finishes a row and a column counts as 2 lines and pays 30, where the same two lines cleared on separate turns pay 10 each.
• Keep room for shapes you have not been dealt yet. The catalogue tops out at a solid 3×3 and bars of 5, and the draw never looks at your board, so an open 3×3 area and a clear run of 5 are worth protecting.
• Place the awkward piece first. The run ends the moment nothing in your tray fits, so the last of the 3 has to go down on the board the first two leave behind — put the shape that needs the most room down while the room is there.
• Use the highlight before you commit. Carry a piece over two or three candidate squares and watch which rows and columns light up; comparing costs nothing, and releasing where it does not fit does nothing.
• Treat Undo as a way of looking. Put a piece down, read the board it leaves you, and take it back if you do not like it — the tray comes back exactly as it was.

Questions people ask