Aleatory contract

An aleatory contract is a contract in which the performance of one or both parties is contingent upon the occurrence of a particular event. The most common type of aleatory contract is an insurance policy. Such an insurance contract may be a boon to one party but create a major loss for the other, as more in benefits may be paid out than actual premiums received, or vice versa.

The term was a classification developed in later medieval Roman law to cover all contracts whose fulfilment depended on chance, including gambling, insurance, speculative investment and life annuities. Many modern forms of derivatives and options may in some cases also be considered aleatory contracts. For example, the French civil code contains a chapter on aleatory contracts, with specific provisions for gaming (gambling) and life annuities.

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