Which type of contract typically does not require equal exchange between parties?

An aleatory contract is a type of agreement where the performance of one or both parties is contingent upon the occurrence of a certain event, and it does not require an equal exchange of value. In an aleatory contract, the parties agree to provide a benefit only if specific conditions are met, often resulting in an unequal distribution of value based on the uncertainty of the event.

For example, in a typical insurance contract, the insurer receives a premium and promises to pay a benefit only if a covered event occurs. The premium paid may be significantly less than the potential payout, which showcases the unequal exchange between what is paid and what can be received.

In contrast, other contract types mentioned usually entail more of a balanced exchange. Conditional contracts depend on the occurrence of a condition, personal contracts are tailored for specific parties and involve mutual promises, and unilateral contracts reformulate the exchange of consideration but still expect a clear benefit from both sides, albeit in different timings. This inherent nature of aleatory contracts makes them unique in not necessitating an equal exchange monetarily or otherwise.