Developed by OZ's Colonel Tubarov, a loyal supporter of the Romefeller Foundation at OZ's Lunar Base, the Mobile Doll System uses a powerful computer system equipped in a mobile suit that allows it to act on its own without a human pilot. Through this method not only would it help prevent Romefeller from sacrificing the lives of their pilots, but it also would prevent them from using poorly skilled pilots in battle. The Mobile Dolls were deadly in battle, because they had faster reaction times than human pilots. However one of the Mobile Dolls chief opposers was OZ's leader Treize Khushrenada who felt that the Mobile Doll system would make humans unnecessary for battle, and therefore render battles useless. After the White Fang seized control of the Lunar Base, the modified ZERO System that the White Fang leader Zechs Merquise had developed allowed Dorothy Catalonia to employ the system in controlling the Virgo II's Mobile Doll target programming and tactics during battle. One other variation is that when the Gundam Scientists who remained as prisoners in the hands of OZ and later the White Fang rebuilt the OZ-13MSX1 Vayeate and OZ-13MSX2 Mercurius into Mobile Dolls. Both of these suits Mobile Doll AI system were equipped with battle data from Trowa Barton and Heero Yuy from when they previously piloted these suits, and were later single-handedly destroyed by Duo Maxwell.
In the creation of the Tallgeese, the MS developers believed they had created a machine too sophisticated to be controlled by a single person. The machine, they said, was perfect – it was the human pilots that were the problem. In order to make it a viable weapon, something had to change.
There were two paths that could make Mobile Suit combat a reality: 1. The human pilot would be eliminated entirely, making the MS an unmanned vehicle. 2. The pilots themselves would be altered to make them perform better.
The former concept evolved into the MOBILE DOLL (MD) program, short for MOBILE Direct Operational Lead Labor. Mobile Dolls required an operating system to be installed on the MS, and some sort of command software outside the MS that would feed it orders. They could be controlled directly, or left to their onboard Artificial Intelligence (AI). Operators need not be fully trained pilots as the AI handles the nuances of control.
Some people saw the creation of unmanned combat MS as a solution to the warfare that long plagued the Earth Sphere. Without the casualties that resulted from traditional combat, the most horrifying aspect of war, death, was all but removed. But the MD was fundamentally a weapon of mass destruction, and when you remove the human element from that destruction, warfare becomes all the more meaningless.
The MD project was funded by the Romefeller Foundation who used MD to take over the UESA. Through the mass-production of MD, they could maintain and expand their command of the Earth sphere without needing to train new pilots. OZ, the group who most relied on manned MS, did not like the move towards unmanned suits, and its leader, Treize, fought against their use by the Foundation. While he proved, at the time, that a human pilot was still superior to an AI, development of MD continued.
The first mass-produced MD were based on existing Leos and Tauruses. The first MS type created as an MD was the Virgo. These were the foundation on which the more advanced Mercurius and Vayeate were created, and later the Virgo II incorporated the best of all worlds, becoming the ultimate MD.
As with all other suits, save the Gundams, after the war ended in December AC 195 all mobile dolls were dismantled or destroyed.