Red herring

From IFWiki

For the UK text adventure fanzine, see Red Herring (fanzine).

A notable or unusual object that seems like it will be potentially useful for solving a puzzle, but actually isn't useful at all. This is distinct from commonplace furnishings and sundries that are included only for atmosphere. Red herrings may be in a game to mislead the player, to make the game world seem bigger than it really is, or just as a joke. Red herrings intended as jokes are often flagged with sly phrases like "crimson fish" or "scarlet eel".

For example, an ignition key for a helicopter is a red herring if there's no helicopter in the game, or, as a famous example, a chainsaw with no fuel in the game or vice versa. Also, a gold coin seen in a fountain (filled with crimson fish, of course) is a red herring if the coin turns out to be a worthless plastic disc when obtained.

See also