Find doors whose key sits behind the door itself

In an adventure with many locked gates, one wrong placement can make the ending unreachable, and you only notice after twenty hours of play. Here is a way to walk the whole map the way a player would and list every gate that can never open.

Why this works

A map is only as good as the walk a real player can make. Reading it by eye hides circles where a key waits behind its own door, so you play the walk in order, collecting and opening until nothing new appears, and report what stayed shut.

When not to use it

Skip it when you place every key by hand in a small adventure you can finish yourself in ten minutes. And it cannot help if keys get used up when opening a door: there the order matters, so test the possible orders instead.

In the full entry

• What to build, step by step
• Starting values and the reason for each
• 4 common mistakes and the fix
• A diagram of every state
• 37 lines of example code with 3 checks that pass
• How your AI shows you that it works

Say this to your AI

Use the Spielerando entry "Find doors whose key sits behind the door itself" (read_entry key-behind-its-own-door-deadlock) in my game. Build it step by step, and show me how you checked that it works.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP