(Metal Gear / Release: 1987)

A powerfully armed nation called "Outer Heaven" is suddenly born deep in the jungles of southern Africa. NATO soon learns that they are at work designing a nuclear-equipped walking battle tank called "Metal Gear", and they send in one of their best agents, Gray Fox. However, after Grey Fox is taken hostage, they are forced to send in the newest member of Fox Hound, Solid Snake. Snake is successful. He rescues Gray Fox and forces the surrender of Outer Heaven. But just as he is planning his escape, he sees one man standing in his way. It's the commander of Fox Hound, Big Boss! As it turns out, Outer Heaven is a large scale mercenary company and Big Boss was the mastermind behind all of it. Big Boss had intentionally chose his most inexperienced agent, Solid Snake, in order to spread disinformation to the West, but he seriously miscalculated. "You've gone too far! Too far!" Big Boss shouts with rage at the man who undid all of his carefully laid plans. After a fierce battle in which Big Boss is defeated, Snake emerges victorious as Outer Heaven burns around him.

(Metal Gear 2: Solid Snake / Release 1990)

Dr. Kio Marv, inventor of the oil refining microbe, OILIX, was taken hostage by Zanzibar, a heavily armed nation in central Asia ruled by a minority ethnic group. Zanzibar was planning to gain political and military hegemony over a world suffering under the cruel weight of a worldwide energy crisis. Roy Campbell, commander of FOXHOUND, called Solid Snake, now in retirement, back to active duty to infiltrate Zanzibar and recover Professor Marv.
Solid Snake made it past Zanzibar's impressive steel wall and penetrated deep into its interior. There he once again destroyed Metal Gear, which had been completed after being transported from Outer Heaven, and defeated Gray Fox, former member of Fox Hound and now leader of the Zanzibar mercenary corps. He was also successful in retrieving the OILIX manufacturing process. Finally, he came face to face with the man who was pulling the strings in Zanzibar, Big Boss! He had survived Outer Heaven and created Zanzibar in order to make a world rife with conflict and war, a world in which soldiers such as himself would always have a place. After defeating Big Boss for the second and final time, Snake gave up on war and retired to the peaceful Alaskan wilderness.

The nuclear weapons disposal facility on Shadow Moses Island in Alaska's Fox Archipelago is attacked and captured by Next Generation Special Forces led by members of FOXHOUND.

The terrorists have got their hands on hundreds of nuclear warheads and they're demanding that the government turn over the remains of Big Boss. They warn that if their demands are not met within 24 hours, they 'll launch a nuclear weapon. Solid Snake is once again called back to duty in a top-secret mission to deal with the greatest terrorist threat the world has ever seen.

His mission is to first single-handedly infiltrate the nuclear weapons disposal site and rescue the two hostages, DARPA chief Donald Anderson and the President of ArmsTech, Kenneth Baker, and then to eliminate the terrorists and prevent a nuclear launch. The time limit is 24 hours. Once again, Snake heads to battle...alone.