How to play Slide Maze

Slide Maze uses the rule sometimes called an ice puzzle: swipe a direction and the block travels until something stops it. It does not move one square. It does not stop where you would like. It stops when it hits a wall or the rim of the board, and not before.

That single change is what turns a trivial maze into a puzzle. In an ordinary maze the walls are obstacles to go around. Here every wall is a **brake**, and the route you are looking for is really a sequence of things to crash into. A square with nothing beyond it is unreachable no matter how obvious it looks, because there is nothing there to stop you.

The gems, and why they are the puzzle

Three gems sit on the board, and the exit will not accept the block until all three are collected. They are picked up by sliding **over** them, not by stopping on them.

This matters more than it sounds. If a gem had to be landed on it would just be another exit, and the game would be three short mazes played back to back. Collecting by passing means a single long slide can sweep up two gems on the way to somewhere else, and it means the order you take them in changes the length of everything that follows.

The difference is measurable. Without gems the average shortest route on these boards is about five moves, which is over before it starts. With three gems it is about twelve. More telling: a player who always heads towards the nearest thing they still need matches the best possible route roughly one time in ten. The ordering is the game.

The Fewest number

The figure marked Fewest is the true minimum number of moves, not an estimate and not the route the generator happened to use when it built the board.

It can be exact because a position in this game is very small: the square the block is standing on, plus which of the three gems it has already collected. That is a few hundred possibilities on the largest board, so the game simply searches all of them and takes the shortest route to the exit. Nothing can be shorter, because the search looked at everything.

Matching it is a perfect run. Going over costs nothing except the number.

Boards are picked to land near a target length rather than to be as long as they happen to come out. An earlier version placed the exit at the farthest reachable position, which sounds harder and produced a ladder that lurched — one level would ask for sixteen moves and a later one for eleven, so the game read as getting easier the further you went. Aiming at a target and re-dealing anything that misses it makes the climb steady.

Getting stuck, and why the game tells you

A careless slide really can leave the block somewhere the exit cannot be reached from. Measured on random play it happens after a single move about one time in twenty, and rather more often over several. It is a genuine consequence of the rule, and removing it would mean removing the rule.

What the game will not do is hide it. After every move it re-runs the same search that produced the Fewest number, and the moment the exit becomes unreachable it says so, marks the move counter, and points at Undo. A dead board that says nothing is the worst version of this puzzle, because you keep playing it.

Undo is unlimited and free, and steps back the gems as well as the square.

Reading a board

Two habits do most of the work.

The first is to look for the brakes rather than the route. Before planning anything, find the walls that stick out into open space — those are the only places the block can stop in the middle of the board, and every useful route runs through one of them. The edges are brakes too, which is why the rim is often the safest way to travel a long distance.

The second is to plan the gems as an order, not as three destinations. Ask which gem you can reach that leaves you somewhere useful, not which is nearest. A gem swept up in passing costs nothing; a gem that leaves the block in a corner with one exit costs several moves getting back out.

The daily maze

One seven-by-seven maze a day, the same for everybody, built from the date. Finishing it extends your streak, your best move count is kept, and the share text carries your moves, that maze's Fewest and your time without giving the layout away.