How to Fix Key-and-Door Progression Softlocks in Generated Levels

If a generated dungeon hides the red key behind the red door, the player is softlocked. Ordering lock placement against reachability prevents that.

How to fix it

1. Compute reachability before each lock

Before placing a locked door, flood-fill what is reachable from the start without that key. The key must be placed somewhere in that currently reachable set.

2. Place the key first, then the door

Put the key in a reachable cell, then place the door on a boundary that gates new territory. The new territory becomes reachable only after the existing key is collected.

3. Validate the whole lock-key chain

After placing all keys and doors, simulate a playthrough that picks up reachable keys and opens reachable doors in a loop. If the exit is not reachable when the loop stalls, the chain is broken and the level must be rejected.

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.