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A Mars Security Guard.

Mars City Security, also shortened to Mars-Sec, is, as the name suggests, the regular security guard unit of Mars City and the adjoining UAC facilities. They have different body armor, rank structure and uniforms than the Marines. This is probably because Mars Security are personal security contractors who work directly for the UAC, as opposed to the marines who work for the Earth government.

While the Mars-Sec seem to share many duties with the Marines, it appears that the Mars-Sec serve as the day-to-day regular UAC Security Guard force, securing clearances for certain areas while protecting other employees from any possible threats. Marines, on the other hand, tend to have more specialized jobs, such as being tasked with guarding special areas around the base (Marine Command for instance), as well as accompanying science teams being sent through the Portal. The security teams for the Delta Labs (Marines and Mars-Sec alike) are specifically selected, due to the unique nature of research conducted inside Delta Labs. Because the UAC provides major funds and weapon research for the military, the government established an active duty Marine base on Mars to assist the UAC with extra security while the UAC continues to conduct research for new military weapons.

During the demonic invasion, a majority of the Mars-Sec personnel were demonically possessed into Z-Secs or otherwise killed.

Known Mars City security personnel[]


While on guard duty, Mars-Sec personnel wear black armor with a helmet. On outside operations and transit, they will have also have a breather equipped.

Standard issued weapons include pistols, shotguns, and machine guns. Some personnel can also be equipped with protective Riot Shields. Mars-Sec personnel also utilize on equipments such as Sentry Bots and automated turrets to ensure more strict security in some areas.