The setup is deliberately small. A guard puts a key in a drawer, the player moves it to a cupboard while he is away, and later he needs the key. If he walks straight to the cupboard, the player calls bullshit — he never saw the move, so he should check the drawer first.
That is the inversion at the centre of this r/gamedesign thread: the author wants an NPC that goes to the wrong place, because being wrong is what proves he is not cheating.
The design questions it opens up:
- If another guard asks for the key, does he get sent to the drawer too?
- When the guard finds the drawer empty, what gives him a reason to suspect the player?
- How much should a player be able to build around an NPC being wrong — a guard searching where he last saw you, a witness blaming the wrong person while you let them?
- The intended feeling: “I came up with this plan myself, and it actually worked.”
The replies push back on cost, and the pushback is the useful part:
- One misplaced key is fine to script; the same rule across a whole game is “more spaghetti than Italy” — so it has to be a core loop, not background detail
- Players probably will not notice the detail on its own, so decide what you want them to feel before modelling anything
- F.E.A.R. is the reference: much of why its AI read as smart came from voice callouts for conditions that did not change its behaviour at all
- Keep the search bounded — the drawer plus a couple of nearby spots already buys the player a window, without the guard needing to solve the mystery
- The best lever is routine: a shift-change handoff tells the player who holds the key and when, so the interesting move is to knock that routine out of sync
The valuable shift here is from “smarter AI” to “legible ignorance.” A guard walking to the wrong place is a visible, one-glance proof that the NPC does not have access to world state he should not have. Perceived honesty is cheaper than simulated cognition — and it only pays off if the player can follow what happened and plan again.