Crate Stack

Six crates in four bays, and one rule: a crate only rests on a heavier one. Move them, one at a time, until the dock matches the manifest — and watch the top weight printed on each bay, because that single number decides every landing you are allowed to make. A crate that reaches its manifest place is bolted down for good, so the order you build in is the whole game.

It runs entirely on your device: 0 network requests, works offline. No ads, no account, nothing to buy, and no betting, money or prizes of any kind.

1. Focus the dock — click it, or press Tab until it is focused.
2. Choose a bay with the left and right arrow keys.
3. Lift the top crate with the up arrow, then set it down on another bay with the down arrow. Enter does whichever of the two makes sense.
4. Press F to jump straight to a bay that can take the crate you are holding, instead of hunting for one.
5. Put it back for free with Esc, or by setting it down on the bay it came from. Only a landing on a different bay spends a move.
6. Read the two numbers: the top weight on each bay is what a landing is tested against, and "shortest from here" is the exact number of moves still needed. Finish before the budget runs out.

How do you solve a crate stacking puzzle?

Work bottom-up, one bay at a time, and decide the floors before you touch anything else. The manifest tells you which crate has to sit on the floor of each bay, and those crates are the only ones with no deadline — everything else has to be out of their way first. So the order is: find the crate each floor needs, work out what is currently sitting on top of it, and move that somewhere it will not be in the way again. The trap is putting a correct crate onto a wrong pile: it looks like progress, it is not, and here it is worse than nothing, because a crate is only bolted down when everything beneath it is right too. The top weight printed on each bay is the whole decision — a crate needs a bay that is empty or topped by something strictly heavier, and no other fact matters.

Is every dock actually solvable?

Yes, by construction. The manifest is drawn first, and then the game searches backwards from it, undoing legal moves one at a time and recording how far each dock is from home. Your opening position is one of the docks that search reached, so the route back is not a hope — it is the exact sequence the search just walked. It is also why the budget is honest: it is the true shortest solution plus four, measured rather than guessed, so par is always achievable and always tight.

Why can a crate get stuck with no legal move at all?

Because two crates of the same weight will not stack, a bay only holds three, and a crate on its manifest square is bolted down. Put those together and a dock can reach a state where every bay that still has room is topped by a crate no lighter than anything that could move — nothing is legal, and the round ends there. That is deliberate: it is the cost of burying something, and a game where burying can always be undone cannot teach you not to do it. You will usually see it coming sooner, though, because the round also ends the moment no route home fits in the moves you have left, and the board says so rather than letting you shuffle.

What does "shortest from here" mean?

The exact number of moves between the dock in front of you and the manifest — not an estimate. It is recomputed after every landing by the same search that built the puzzle. One landing always changes it by exactly one, so it is the honest scoreboard for whether the move you just made helped: down by one, you are on the shortest line; up by one, that move cost you two of your spare, because you also spent the move itself.

Do I need to see colour to play this?

No. Every crate carries its weight as a number and as its width, the crate in the crane is marked with an arrow and a dashed edge, and a bolted-down crate carries a tick. Bays that match the manifest say so in words. The puzzle is complete in greyscale and in forced-colours mode.

Is there any money, betting or in-app purchase in this?

None, and there never will be. No currency, nothing to buy, no extra bays for sale, no wager of any kind.

Can I play it with a keyboard or a screen reader?

Both. Arrows choose a bay and work the crane, Enter does either, F jumps to a bay that can take the crate, and Esc puts it back. Each bay announces its crates from the floor up, its top weight, what the manifest wants there and whether anything on it can still be lifted.

Does it work offline?

Yes. Once the page has loaded once, the whole game is on your device. There is no server involved in play at any point, and no account to lose your progress behind.

Six crates, four bays, three crates to a bay, weights one to six. Openings are dealt from five to eight moves out with a budget of four spare — enough for two wrong turns, since a landing that does not help costs both the move and the extra step it adds. The dock is one row of four, so it fits a narrow phone without scrolling.

Colour Sort is the other stack puzzle here and rewards the same habit — decide the end state first, then make every move serve it. Slide Fifteen teaches the discipline from the other side: work in a fixed order rather than fixing whatever looks worst.

Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.