War Games 1983

A young man finds a back door into a military central computer in which reality is confused with game-playing, possibly starting World War III.

A young computer whiz kid accidentally connects into a top secret super-computer which has complete control over the U.S. nuclear arsenal. It challenges him to a game between America and Russia, and he innocently starts the countdown to World War 3. Can he convince the computer he wanted to play a game and not the real thing?