What type of contract is defined as one whose outcome is affected by chance?

An aleatory contract is defined as one whose outcome depends on an uncertain event or chance. In such contracts, the performance of one or both parties is contingent on the occurrence of an event that is uncertain, meaning that the benefits or losses are not guaranteed. A common example of an aleatory contract would be an insurance policy, where the insurer agrees to pay a certain amount only if specific events—like a loss or damage—occur.

This characteristic of unpredictability distinguishes aleatory contracts from other types, such as commutative contracts, which have a guaranteed and mutual exchange of value. Conditional contracts are similar in that they also depend on certain conditions being met, but they do not necessarily involve the element of chance. Contracts of adhesion are standardized contracts offered on a take-it-or-leave-it basis, which do not inherently involve uncertainty regarding their outcomes. Therefore, the defining feature of an aleatory contract is its reliance on chance, which makes it the correct choice in this context.