When the lack of excitement for a film is reversed by the surprisingly good experience the film turns out to be. The opposite of the Prometheus Effect.
Usage: Dredd turned out to be a much better film than we expected it to be, so we experienced the Dredd effect when we saw it.
Usage: It's a shame more people didn't go see Rise of the Guardians -- they would've really been hit with the Dredd effect, liking it much more than they ever thought they would.
First Used: 28 Days Later