Block Stack

Ten cells wide, and the wall is the real opponent

The board is ten cells across and twenty tall, and the queue of three tells you what is coming. Nothing here can kill you except height, so the pile is the only opponent. Watch the top of your stack, not the piece in your hand: a piece over an empty board has four good places to go, and one arriving at row fourteen has exactly one. Spend your first pieces flattening the floor, even at the cost of a hole you would rather not have. An uneven floor is a debt you pay on every piece that follows.

The seven shapes, and the three that misbehave

The long piece, the square and the T build well in any stack. The long one clears four rows at once and wants one thing: a column four cells deep. The square fills a two-cell notch without changing your skyline, which is why a two-wide pit is worth leaving and a one-wide pit is not. The S and the Z ruin a flat floor if you let them land wherever is convenient: both have a step, and a step on flat ground becomes an overhang two rows later.

Rotating in a corner, and what the game will not do for you

Rotating beside a wall does not simply fail. The shape turns inside its own square box and the game then looks for somewhere to put it: where it stands, one cell left, one cell right, then up. That order is why a piece jammed against the right wall slides a cell away from it, and why the same move on the left wall slides the other way. What the search will not do is drop the piece to make a rotation fit. There is no downward nudge in the list, on purpose: a rotation that only works by sinking into the stack would bury a cell you needed. When a rotation refuses, move a cell away and try again.

Every line has a price, and the level multiplies it

One row is 100, two at once is 300, three is 500, four is 800 — and all of it is multiplied by your level. That is the whole argument for keeping a four-row gap open: four separate clears at level five pay 2,000, and one long-piece clear pays 4,000, for the same work. Soft drop pays 1 point a cell you push down; a hard drop pays 2 a cell it falls on its own. The level rises every ten lines and changes the speed, not the board. Level one drops a piece about every four-fifths of a second, level five closer to a third, level ten about a seventh. The multiplier never stops climbing.

The hold slot is a plan, not a panic button

C parks the piece in your hand and brings out whatever is in the slot; pressing it again swaps the two. You get one per piece, and the slot refills the instant a piece locks, so it is a tool you use every seven or eight pieces. Hold early and hold for a reason. If the third piece in the queue is the long one and your stack has a four-deep column waiting, hold the first, play the second, then take the long one out when the column is ready. The mistake is holding to escape a piece you dislike, then pressing again on the next one. That second press is not there.

Why it is built this slowly, and then suddenly not

The first two minutes are meant to be calm, because a stack is only interesting if you built it. The speed curve stays polite until about level six and then stops asking. Rotation is deliberately predictable rather than clever: the game looks for somewhere to put the piece in the same fixed order every time, so a move you learn once keeps working.

What do I do when no long piece is coming?

Fill in beside the pit, not into it. A two-wide opening accepts the square, the S, the Z and anything laid flat, and it will still take a long piece later — a single-column pit will not. The queue of three tells you this four pieces early, so you are never guessing.

Can I hold more than once with the same piece?

No. The slot opens when a piece locks into the stack and closes the moment you use it, so it is one swap per piece, not per drop. If you swap a piece away and immediately want it back, it is already spent — play the piece in your hand and hold the next one.

Why did a rotation do nothing at all?

The shape was blocked in every position the game is willing to try: where it stood, one cell left, one cell right, one cell up, two cells up, and two cells left or right. Move a cell away from the stack and turn it again, or try the other direction. Nothing is broken.

How long have I got after a piece touches down?

About half a second, and the clock restarts each time you slide or turn the piece while it is resting on something. You get fifteen of those restarts per piece. After that the next time it settles it locks immediately, so a long wiggle at the bottom of a narrow gap will run out.

Is it worth hard-dropping everything?

Only for the last piece of a run. A hard drop pays 2 points a cell but it takes away every chance to tuck the piece under an overhang, and a tuck is worth far more than the points. Use hard drops to end a piece you have already placed, not to place it.