Woodoku

Leave yourself room

Woodoku punishes greed. There's no gravity here: blocks stay exactly where you drop them, and nothing shifts until you complete a full row, column, or 3x3 box and it clears. So the board only ever gets more crowded unless you're actively clearing lines, and the game ends the moment none of your three current blocks can fit anywhere. The players who last aren't the ones landing the flashiest combos; they're the ones who keep the most open space.

Look at all three blocks before you place the first. You have to fit the whole set, so plan the awkward one (the big square or the long five-in-a-row) first, and slot the small pieces into whatever's left. Filling the middle of the board with a stray single because it was convenient is exactly how you end up unable to place a 3x3 square three moves later.

Placement theory

Fill from the edges in

Corners and edges are where dead space is born. A corner cell belongs to one row, one column and one box, with only two neighbours to help finish any of them, so junk left there tends to stay there. Send your awkward placements to the rim early, while you still have choices, and keep the middle (the cells with the most ways to be cleared) as your flexible working area. A practical target: keep one full 3x3 region near the centre clean at all times. That's your landing zone, and it's the difference between surviving a bad tray and not.

Plan for the piece you don't have

The tray shows three blocks, but the real opponent is the next tray, which you can't see. Two shapes define your safety margin: the 3x3 square and the straight five. If the board can accept both right now, you're healthy; the moment neither fits anywhere, you're gambling. Small blocks are caulk: their job is to tidy the edges of whatever the big pieces leave behind, not to claim prime real estate just because they were easy to place.

Clears, combos and the boxes

A line clears the instant it's full, and finishing a row, a column, and a box in overlapping spots can clear several at once for a combo bonus, the fastest way to score and the fastest way to free space. Because Woodoku borrows sudoku's 3x3 regions, watch those boxes as closely as the rows. A worked case: say the top-right box is missing only its bottom three cells, and the row those cells sit in is complete everywhere else. Lay a horizontal three-piece into the gap and the box and the row vanish together: one block, a double clear, and the bonus that comes with it. Engineering those overlaps on purpose, rather than waiting for them to happen, is most of the difference between a high score and a long survival.

• Try to complete a box and an intersecting row with the same block for a two-for-one clear.
• Keep at least one wide-open region for the big blocks you can't predict.
• Don't chase a combo if setting it up boxes you in. Survival comes first.
• Corners and edges are easy to strand, so fill them deliberately rather than as an afterthought.

Where games actually die

Fragmentation, mostly: not one big mistake but twenty small conveniences. A single cell left between two blocks here, a stray square dropped mid-board there, until the grid is a lace of one-cell holes that only single squares can fill, and the tray owes you no single squares. Judge your board by the largest clean rectangle it contains, not by the raw count of empty cells: forty scattered empties can be a lost position while twenty tidy ones are comfortable. The other habit worth breaking is placing the tray pieces in the order they're shown. The order is yours to choose, and it matters. Often the right sequence is the awkward piece first, then a small piece that finishes a line, so the clear opens room for the third. Play each tray as one three-part move, not three separate decisions. And take small clears when they're offered; holding out for a spectacular combo while the board silts up is how a five-hundred-point ambition turns into a three-hundred-point game.

Sudoku without the numbers

Woodoku takes sudoku's grid and its row-column-box rule and throws out the arithmetic, swapping digits for wooden blocks you place by hand. The lineage is short and easy to trace: 1010! made the drag-three-blocks, no-gravity formula a mobile staple around 2014, Blockudoku bolted on sudoku's 3x3 boxes, and the wood-grain remake carried the idea to one of the biggest puzzle audiences on mobile. Underneath sits a much older toy (polyomino packing, the same family of shapes mathematician Solomon Golomb named in the 1950s), and that mix of old geometry and modern pacing is what gives the game its just-one-more-block pull, the one that keeps people playing well past the point they meant to stop.