Star Trek: The Next Generation - Season 5 Episode 6 -

Stardate: 45208.2 - An addictive game is distributed among the crew of the Enterprise, however, it appears that this game interferes with a person's logic and reason, which leaves the crew open to manipulation. Only a young Ensign and a vacationing Wesley Crusher are able to think for themselves, and must find a way to reverse the damage before the ship falls into the wrong hands.