Environmental storytelling
Also said as Staged spaces, What happened here
Arranging a place so that the player works out what happened there. Don Carson brought the idea to games in a 2000 article, borrowing it from theme park design.
Players trust what they deduce more than what they are told, and the player keeps moving while it happens. A few moved props can cost less than one line of voice acting.
Say it
“Stage this cabin so players can tell someone left in a hurry: two bowls on the table, one chair jammed under the door handle, boots still by the bed. No notes, no voice-over.”
Where you’ve seen it
Portal's test chambers look spotless, until a loose panel shows the scrawled den of someone who got out, with "the cake is a lie" on the wall. Nobody says a word, and you stop trusting the voice guiding you.
Not to be confused with set dressing
Set dressing makes a place look nice. Environmental storytelling makes it say something: take one prop away and a fact about the past goes with it.