Res nullius Law and Legal Definition
Res nullius literally means nobody’s property or a thing which has no owner. If the owner of a property abandons his/her property then that property is called res nullius. Such property is as much res nullius as a property that is ownerless. Res nullius is ownerless property and it can be owned by any person. The person who takes first possession of the res nullius is the owner of that property. Res nullius includes wild animals and abandoned property.
Res nullius also refers to the principle by which a nation may assert control of an unclaimed territory. By this principle, a nation gains control when one of its citizens enters the territory.