A.M.W.S. (Assault Maneuver Weapon System, pronounced "aims") mecha are larger than A.G.W.S. but not as powerful as E.S. units. The major difference between an A.M.W.S. and an E.S. is that the E.S. are equipped with Anima Relics. Two popular A.M.W.S. are the Scutum and Pilum, piloted by Ormus/U-TIC officers Hermann and Richard respectively. Another popular A.M.W.S. was a machine piloted by Jin Uzuki during the Miltian Conflict. The green, agile mecha closely resembled the gear Heimdal which was piloted by suspiciously familiar Citan Uzuki of Xenogears. Jin's A.M.W.S. was capable of slicing other mecha literally in two with its signature weapon, a massive sword. The unit is abandoned after sustaining heavy damage during a battle with multiple rogue Federation A.M.W.S.s and is not seen again. Some other A.M.W.S. use melee weapons, but many units are equipped with projectile or energy weapons.
A.M.W.S. units are similar to the "Gears" from Xenogears. In Xenogears, "Gears" received energy from the Zohar; however, in Xenosaga, A.M.W.S. units do not appear to use it as their source of power. In Xenosaga Epiosde I, most of the mecha were merely of the A.G.W.S. variety. In Episode II, many antagonist factions used A.M.W.S. units to counter the E.S. robots piloted by the main characters.