The Mark III Armor was Tony Stark's third Iron Man suit and an upgrade from the Mark II, improving on its previous flaws. It was the first suit to integrate an advanced on-board weapons system and was the first to adopt the standard red and gold color scheme.
After nearly perfecting his Mark II armor, Tony Stark discovered a nearly fatal icing problem in the suit during a high altitude test flight after which he decided to move on to develop the Mark III suit.
Stark later solved the suit's icing problem by using a gold-titanium alloy from an earlier satellite design that wasn't prone to freezing. He also opted to integrate a new, miniaturised weapons system that was concealed by the suit's exterior plating. Once the armor was ready for assembly J.A.R.V.I.S showed Stark a preview of the finalised design. Stark disliked the armor's new coloring due to the new materials used so he personalised it with a red paint job.
The Mark III was destroyed when Tony Stark's Mansion came under attack by Mandarin's forces. Damage to the mansion's systems cause the suit to unintentionally detonate .
Tony Stark was able to solve the icing problem, which was the biggest design flaw of the Mark II, by substituting the same metal that was used in Stark tactical satellites, which was far less prone to freezing, into the suit's new design. The suit now allowed Tony to speak on the phone using his own cellular's phone number, however if used when flying the loud noise of the wind made it difficult for Tony to hear the other speaker.
Like the previous suits, the Mark III enhanced the user's physical capabilities, granting them near superhuman level strength (which the Mark III proved is enough to lift a car), near bullet-proof durability, and enhanced movement speed and reflexes.
Stark also decided to integrate his own advanced, miniaturised weapons system concealed beneath the suit's exterior plating. This included a set of mini-guns concealed in the shoulders of the suit that could fire a total of twelve shots at a time, six from each shoulder, and used a computer guiding system to fire at multiple individual enemies, in different positions, at the same time. The suit contained a small set of miniaturised, high explosive missiles, concealed in each forearm, each capable of taking out a full size tank.
The Mark III also contained a set of non-weaponized flares contained in two circular launchers located at the suit's hips. Stark has used these on at least two occasions: to distract the two F-22s that were pursuing him in the skies over Gulmira, and to temporarily blind the Iron Monger in their fight.
In addition to the other weapons, Stark upgraded the energy output of his repulsors to weapons grade levels after which they have become the standard weapons of every Iron Man armor since. Stark also modified the suit to fire unibeams or beams of concentrated energy, siphoned straight from the arc reactor, and shot through the aperture on the suit's chest.