Domain Expansion is a technique used in Jujutsu Kaisen that allows a Jujutsu Sorcerer to manifest a barrier within their innate domain and trap their opponent inside it. It is achieved by expanding ones innate domain with cursed energy while using a barrier to construct it inside a separate space. Once a Domain Expansion is unleashed, the chances of an attack within the domain hitting the users target is guaranteed. However, there are several facts that may decrease the chances.

Before Domain Expansion, a sorcerer must first manifest their innate domain, which is the manifestation of a user’s powers, abilities, and personality that exist within their mind. This kind of domain is usually cannot be seen by other people, and most Jujutsu Sorcerers can’t even see their own innate domain. But once somebody is able to utilize their cursed energy properly, then a domain should manifest inside them.

It is important to note that only two humans have been shown to use Domain Expansion, Gojo and Megumi, and it is incredibly rare and costly to use. Even Supreme First-Grade (and most special-grade) sorcerers have not been shown to use them. There are also anti-domain techniques that have been invented to counter them.