Board Thread:General Discussion/@comment-7431551-20140405020542/@comment-192.160.117.141-20140407090253

What 166 said. The series goes to some pains to justify the damned things; all three of the prequel games showcase the concept in a different stage of development.

1964 - Shagohod: A weapon designed to replace stationary missile silos. It uses a road or runway to build up speed to lob an ICBM.

1970 - ICBMG: Sort of an ICBMIRV. At this point, the legs that will define later MGs are no more than landing struts.

1974 - Peace Walker: The first properly-legged vehicle, intended to be capable of traversing the extremely varied and rugged terrain of Central America. There's a lot of NASA rover DNA in this design. I'm not sure how far these things are supposed to be able to throw missiles.

By this point, we can finally justify:

1974, 1995, 1999 - Metal Gear ZEKE and Metal Gear D: The archetypical Metal Gear; a mobile nuclear launch platform. The small size makes it preferable to silos for small outfits like MSF. D is basically a direct upgrade from ZEKE.

2005 - Metal Gear REX: I'm not actually sure what the U.S. wanted from this design. It's possible that it was essentially just supposed to be the concept of Metal Gear D, but with the development budget of a real country behind it. Aside: Big Boss had to invent a giant helicopter to move D around; I have no idea how the army was planning on transporting REX.

In Metal Gear Solid 2, the Metal Gear lineage diverges into two:

2007 - Metal Gear RAY: At this point, "Metal Gear" no longer refers to a nuclear weapon, but to any tank with legs; RAY is a weapon designed to actually engage enemy forces as anything other than a last resort, and it doesn't carry a nuclear payload. It appears that by this point, the technology behind legs is good enough that you no longer need to come up with pages of justification to put them on a tank without anyone looking at you funny - conventional warfare after this point will see increased emphasis on UMGs, which are basically RAY in different sizes.

And, on the side of nuclear weapons development:

2009 - Arsenal Gear: A weapon designed to launch nukes at the Internet. What a time to be alive.