From publisher blurb:
Gearing up for adventure can be complicated. You have to find a suit of armor that offers you the right balance of protection, flexibility, and weight, and sort through a list of hundreds of options to find the deadliest weapon that suits your skills. Then, you have to pick a different weapon, because the weapon you actually wanted is too expensive for you to afford for three more levels.
Fortunately, since this is a game, and characters only have to pick from stock supplies when it’s convenient for them to do so. There’s nothing stopping a character from commissioning or creating a custom piece of work - at least, not with Adaptive Armory.
Outside of their own abilities, the equipment an adventurer chooses to use are their most valuable tools. A reliable weapon and sturdy armor are unparalleled assets.
In the Starfinder Roleplaying Game Core Rulebook, there are hundreds of unique weapons and nearly a hundred different kinds of armor. Despite this, the options for custom gear are minimal at best, restricted to a few add-ons each level through upgrades and fusions. There aren’t any rules for fully customized gear, and the gear that does exist is irregularly spaced out between what damage it does and what level it is available - forcing characters to dramatically change their loadout every level or wait painstakingly long between upgrades.
That’s what the Adaptive Armory is for. These rules allow for the creation and upgrading of weapons and armors of any style and any level, tailored to the character who created it. If you want a laser rifle, you can make that! If you want a laser rifle that can also fire blasts of flame or grenades? or... a death ray that fires a beam of flesh-melting energy, and needs four hands to fire? You can do that too.
Best of all, not only does Adaptive Armory contain rules to make tens of thousands of unique weapons and at least a thousand unique armors, and more rules to upgrade any armor or weapon you might have, it also contains appendicies with 720 pre-made weapons, and 180 pre-made armors!