The world of Mobile Suit Gundam: Iron-Blooded Orphans. Humanity has expanded into space, with settlements on Mars and Venus. The era is P.D. (Post-Disaster), with the calendar beginning on the day the Calamity War ended.

MS (Mobile Suit): Giant humanoid weapons. Normally, it takes several years of training to master their operation.

MA (Mobile Armor): Large unmanned weapons that act to exterminate humanity. They were created 300 years ago based on an ideology promoting total mechanical automation. Most have been lost, but they are occasionally unearthed from underground.

Gundam: 72 MS units built 300 years ago to counter the MAs. They utilize a common internal structure called the Gundam Frame and are named after the demons of Solomon. They demonstrate their true potential through the Alaya-Vijnana System. Currently, only 26 units are known to exist; the rest have been destroyed or lost. They are equipped with two Ahab Reactors in parallel, boasting output far superior to standard MS. Equipment is often compatible between Gundam units. Their existence is not common knowledge.

Alaya-Vijnana System: A system that connects a human to an MS by embedding nanomachines into the spinal cord. By feeding MS data directly to the pilot, it achieves incredible reaction speeds and mobility. It places a massive burden on the pilot's brain, and in the worst cases, can lead to death. The surgery carries high risks; some have been paralyzed from the waist down just by undergoing it. It allows even untrained individuals to move an MS intuitively. Multiple nanomachines can be implanted, but the risk of failure increases with each one. The surgery can only be performed on children during their growth period.

Limiters: Gundams are equipped with limiters that restrict their performance. The pilot can choose to release them, causing the unit's eyes to glow red. This places a severe strain on the pilot and can cause permanent disabilities such as blindness or paralysis.

Ahab Reactor: A power source used in MS and spaceships. It is a semi-perpetual engine and is considered physically indestructible. Standard MS have one, while Gundams are equipped with two.

Calamity War: A war 300 years ago where MAs went berserk and attempted to exterminate humanity. A quarter of the population was killed. The Gundams and Alaya-Vijnana System were developed in the late stages of this war to bring it to an end.

Nano-Laminate Armor: A special paint applied to MS and MA armor. It provides high defensive capabilities. Because of this, beams and long-range attacks are rarely decisive, making close-quarters combat the standard theory of engagement.