How does the maze game work?
You start in the top-left corner and the exit is the green square at the bottom right. Arrow keys, WASD or a swipe slide you along a corridor until it turns or branches; a tap on a cell in a straight, open line moves you straight there. The clock starts on your first move, so you can look before you go.
Every maze is new, built by the game when you press Start, in a 10 × 10, 15 × 15 or 20 × 20 grid. Each one is a perfect maze: every cell can be reached and there is exactly one route between any two cells, with no loops.
How is your Maze time calculated?
Your result is your time, from first move to the exit, and an efficiency rating. Steps count every cell you pass through, dead ends and doubling back included. Efficiency compares the one route out with your steps: take the route and nothing else and it is Perfect.
Up to 15% more steps than the route is Excellent, up to 35% more is Good, and up to 80% more is Fair. The route is found by a breadth-first search over the maze when it is built, and the site's tests check that the mazes it builds are perfect and that the search finds a connected path from corner to corner.
How long is the way out?
Much longer than corner to corner. A straight run across a 15 × 15 grid would be 28 steps, but in 400 of this game's 15 × 15 mazes the route out averaged 93 steps. These mazes are built by a randomised depth-first search, the “recursive backtracker”, which makes long, winding corridors and relatively few dead ends.
| Maze | Corner to corner | Route out (average) | Dead ends (average) |
|---|---|---|---|
| 10 × 10 | 18 steps | 46 steps | 12 |
| 15 × 15 | 28 steps | 93 steps | 24 |
| 20 × 20 | 38 steps | 153 steps | 42 |
Figures from 400 mazes of each size, made by the game's own code with a fixed seed so they come out the same every time.
Does keeping one hand on the wall work?
Yes, in these mazes it always does. Keep your right hand (or left) on the wall and walk, and in a maze with no loops you are bound to reach the exit, because you trace round the whole maze if you have to. It is rarely quick: in the same 15 × 15 mazes the right-hand rule took 195 steps on average, about 2.1 times the route.
- Look ahead before you move. The clock waits for your first move, so tracing a route by eye, from the exit backwards as well as from the start, costs nothing.
- Follow the trail. The faint line shows where you have been, so you can see which branches you have already tried.
- Dead ends are free to rule out by eye. A corridor that ends in a wall you can see doesn't need walking.
What can affect your Maze time?
Mostly the maze itself: some routes run close to the edge and some wind through the middle, so times vary from maze to maze even for the same player. Size matters most; a 20 × 20 maze has four times the cells of a 10 × 10. On a small screen the 20 × 20 corridors are narrow, so swipes or keys work better than taps there.
For another puzzle with a shortest answer, try Traffic Jam or the Tower of Hanoi.