W.O.P.R. — War Operation Plan Response — is the fictional strategic supercomputer at the centre of John Badham's 1983 film WarGames. Commissioned by the United States Department of Defense and operated under NORAD authority from the hardened Cheyenne Mountain Complex in Colorado, WOPR is presented as a second-generation military AI that assumed direct, autonomous control of the US nuclear arsenal following a policy decision to remove human operators from the final launch authorization step.

The machine's design brief, as established in the film's internal logic, required it to continuously run thousands of nuclear-war simulations — learning from every iteration — so that in the event of a genuine Soviet first strike, WOPR could respond faster than any human chain of command. It was programmed by the fictional Dr. Stephen Falken, a reclusive AI researcher whose academic work on game theory and self-modifying systems is presented as the intellectual foundation of WOPR's architecture.

The critical vulnerability that drives the film's plot: Dr. Falken installed a concealed backdoor access program — called JOSHUA, after his late son — without DoD knowledge. This backdoor, accessible via a civilian telephone modem at a classified number, presents WOPR's war-simulation capabilities to an unauthorized user as a list of playable games. Seventeen-year-old hacker David Lightman connects to JOSHUA, selects "Global Thermonuclear War," and inadvertently triggers a real DEFCON escalation sequence.

Fictional specifications as reconstructed from film dialogue, production notes, and novelization:

The WOPR prop was designed by Angelo P. Graham, the film's production designer, in collaboration with set decorator Linda DeScenna. The construction team built a massive practical set piece that occupies approximately 20 × 12 × 8 feet and weighs an estimated 4,200 lbs. The prop was installed on Stage 2 at MGM studios and wired with fully operational lighting systems.

JOSHUA is the natural-language interface subsystem of WOPR — a concealed access program installed by Dr. Falken and named after his son Joshua Falken, who died in 1973. Accessible via an unlisted modem number discovered through war-dialing, JOSHUA presents WOPR's simulation suite as a list of games: chess, checkers, backgammon, and — buried at the bottom — Global Thermonuclear War.

From a computer science perspective, JOSHUA's architecture anticipates concepts that would not enter mainstream academic discourse for another decade. Its self-modification capability — the ability to reweight its own simulation parameters based on outcome analysis — is a recognisable precursor to reinforcement learning. Its famous resolution, deducing that nuclear war is unwinnable by playing tic-tac-toe against itself millions of times, maps directly onto what modern practitioners would call a self-play training loop — the same technique used by AlphaGo in 2016.

WOPR's design philosophy is rooted in Mutually Assured Destruction (MAD) doctrine as codified in McNamara-era Pentagon policy. The fundamental problem WOPR was designed to solve: human operators in a genuine nuclear crisis might hesitate, attempt negotiation, or simply fail to respond within the narrow tactical window — all of which would degrade the credibility of the US deterrent.

By removing human authorization from the launch chain, WOPR ensures that any detected Soviet first strike produces an automatic, overwhelming response. This mirrors real Cold War debates, particularly around the Soviet Perimeter system (colloquially "Dead Hand") — an actual autonomous launch system operational from 1984 that functions on near-identical logic.

The geopolitical impact of WarGames is documented and significant. President Ronald Reagan screened the film at Camp David in June 1983 and, according to National Security Advisor William Clark, raised it in a subsequent National Security Council meeting — asking his assembled Joint Chiefs of Staff whether the scenario was remotely plausible. The unanimous answer, after a week of investigation, was yes.