(in land law) An interest in land that depends on the occurrence of an uncertain future event. A bare possibility, such as a spes successionis, i.e. a person's expectation of inheriting land under the will of a testator who is still alive (i.e. depending on the testator dying without having revoked the will), confers no legal or equitable interest. A possibility coupled with an interest (e.g. B's rights under a conveyance “to A for life, and if C is living at A's death then to B”) can be transferred by will or by deed. See also possibility of reverter; tenant in tail after possibility of issue extinct.