There are 4 rules or norms to live by in order to avoid all possible conflicts involving scarce rivalrous resources.
Every person is the exclusive owner of their body. (Who else has a better claim to my body than me?)
Every person is the private or exclusive owner of all nature given resources that he perceives as scarce and appropriates for the first time i.e. original appropriation. (Who has a better claim to the property than the original appropriator?)
Every person who produces a good with the help of his body and his justly appropriated property is rightfully the owner of that good or property.
Once a good has been originally appropriated or has been produced, ownership can only be acquired by voluntary transfer from a previous owner to a later owner.