What is meant by a conditional subsequent?

A conditional subsequent refers to an event or condition that, if it occurs, can terminate an existing right or obligation within a contract. This concept is crucial in the realm of contracts because it allows parties to establish certain stipulations that can lead to the loss of rights or interests if a specified condition materializes.

For instance, in an agreement where a party has a right to continue receiving certain benefits, the contract may stipulate that if a specific event occurs, such as a breach of duty or non-performance of an obligation, those benefits would cease. This mechanism helps in defining the circumstances under which one party's rights can be revoked or altered.

Recognizing this, the other options do not accurately describe a conditional subsequent. One option discusses conditions necessary for contract validity, another mentions granting rights contingent on conditions, and the last one addresses ensuring the fulfillment of obligations, none of which directly involve the termination of rights based on conditional events.