During a surprise nuclear attack drill, many
USAF Strategic Missile Wing controllers prove unwilling to turn the keys required to launch a missile strike. Such refusals convince Dr. John McKittrick and other
NORAD systems engineers that missile launch control centers must be
automated, without human intervention. Control is given to a NORAD supercomputer known as WOPR (War Operation Plan Response, pronounced "
whopper"), or Joshua, programmed to continuously run war simulations and learn over time. David Lightman, a bright but unmotivated
Seattle high school student and hacker, uses his
IMSAI 8080 computer and
modem to access the school district's computer system and change the grades for himself and his friend and classmate, Jennifer Mack. Later, while
wardialing numbers in
Sunnyvale, to find a computer game company, he connects with a system that does not identify itself. When asking for games, he finds a list that includes
chess,
checkers,
backgammon, and
poker, along with titles such as "Theaterwide Biotoxic and Chemical Warfare" and "Global Thermonuclear War", but cannot proceed further. Two hacker friends explain the concept of a
backdoor password and suggest tracking down the Falken referenced in "Falken's Maze", the first game listed. David discovers that Stephen Falken was an early
AI researcher and guesses correctly that the name of Falken's deceased son (Joshua) is the password. Unaware that the Sunnyvale phone number connects to WOPR at the non-public U.S. military installation at
Cheyenne Mountain, Colorado, David initiates a game of Global Thermonuclear War, playing as the
USSR while targeting American cities. The computer starts a simulation that briefly convinces NORAD military personnel that actual Soviet nuclear missiles are inbound. While they defuse the situation, WOPR nonetheless continues the simulation to trigger the scenario and win the game, as it does not understand the difference between reality and simulation. It continuously feeds false data, such as Soviet bomber incursions and submarine deployments to NORAD, prompting them to raise the
DEFCON level toward retaliation that will start
WWIII. David learns the true nature of his actions from a news broadcast, and the
FBI arrests him and takes him to NORAD. He realizes that WOPR is behind the NORAD alerts, but he fails to convince McKittrick that he is not working for the Soviets and is detained to await arraignment on espionage charges. David escapes NORAD by joining a tourist group and, with Jennifer's help, travels to an island off the coast of
Oregon where Falken lives under an assumed name. David and Jennifer find that Falken has become despondent, believing that nuclear war is inevitable and as futile as a game of
tic-tac-toe between two experienced players. The teenagers convince Falken to return to NORAD and stop WOPR. WOPR stages a massive Soviet
first strike with hundreds of missiles, submarines, and bombers. Believing the attack to be genuine, NORAD prepares to retaliate. Falken, David, and Jennifer convince military officials to delay the
second strike and ride out the supposed attack until actual weapons impacts are confirmed. When three targeted American bases report no impacts, NORAD prepares to cancel the second strike. However, WOPR locks the staff out and tries to launch the missiles itself, using a
brute-force attack to obtain the launch code. Without humans in the control centers as a safeguard, WOPR will be able to launch the missiles as soon as it determines the correct code. Falken and David direct the computer to play tic-tac-toe against itself. This results in a long string of draws, forcing the computer to learn about futility and no-win scenarios. WOPR obtains the launch codes, then cycles through all the nuclear war scenarios it has devised, finding that they all result in draws as well. Having discovered the concept of
mutual assured destruction ("WINNER: NONE"), the computer tells Falken it has concluded that nuclear war is "a strange game" in which "the only winning move is not to play." WOPR relinquishes control of NORAD and the missiles and inquires, "How about a nice game of chess?" ==Cast==