SPOILERS OF EVERY MGS GAME EXCEPT MGS2 FOLLOW**********
in chronological order
MGS3: Inexperienced soldier Naked Snake and his group the FOX unit gets involved in a bunch of bull**** that makes everything think he's the greatest soldier of all time., earning him the title Big Boss.
MGS
O: Fox unit breaks their allegiance to CIA, and Big Boss is accused of treason as a result. anyway, Big Boss defeats the rebels, and establishes FOXHOUND.
MG: Big Boss starts working on a new bipedal nuke launcher called Metal Gear in a nation he established called Outer Heaven. In order to keep the US government in the dark, he pretends as if he is the one investigating Outer Heaven, by sending in the most inexperienced person in his squad, Solid Snake. However, he underestimated Snake, who finds out about the whole plan and destroys metal gear
MG2: Big Boss escaped in the last game, only to establish a new nation called Zanzibar Land and try the same **** again. Only this time, Snake's good friend Grey Fox is helping him. Snake against foils their plans but this time finishes the deal, killing Big Boss and his friend Grey Fox. Snake says **** this ****. I quit.
MGS: Alas, Snake is called out of retirement. Big Boss's old group FOXHOUND, (because of Liquid Snake) out of nowhere revolts against the US and threatens to launch a nuke. They don't tell him that they have a new Metal Gear but Snake quickly realizes tihs. he defeats FOXHOUND and learns that the main purpose of his mission was to kill off people the US Government found threatening through the use of FOXDIE some kind of **** in Snakes body that kills certain people he comes into contact with. it is also designed to kill snake himself, but Naomi Campbell who originally had it out for Snake because he killed Gray Fox, her brother, feels sorry for Snake and reprograms FoxDie. we also learn that liquid and solid snake are clones of Big Boss in an attempt by the US Government to make a duplicate of what they considered the "perfect soldier". Liquid says that Snake got all the good genes while he got all the bad one. But we learn that in fact both of them got recessive genes and that there was a third brother, Solidus Snake (who was the President of the United States at the time) who got the dominant genes. Roy Campbell the commanding officer declares that Snake has been killed, to stop the Government from looking for him.
MGS2: Snake and otacon break their ties with the government and start their own group to investigate a new Metal Gear that supposed to be superr bad ***. I won't say much since you said not to spoil it, but i will say that it raises tons of questions, some of which MGS3 answered, and the rest which we hope to have answered in MGS4
