How to Fix Generated Levels With No Valid Path From Start to Exit

A level you cannot finish is the worst procedural failure. A connectivity check between start and exit, run before the player ever loads in, catches it.

How to fix it

1. Flood-fill reachability from start

Run a flood fill or BFS from the start cell across walkable cells. The set of visited cells is everything the player can reach.

2. Place the exit only in the reachable set

Choose the exit from cells the flood fill reached, ideally far from the start, so it is guaranteed traversable. If the exit is fixed, connect its region to the start's region with a carved corridor.

3. Reject and regenerate as a backstop

If you cannot place or connect a reachable exit within a few attempts, discard the level and generate a new one. Never ship an unvalidated level to the player.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.