An aleatory contract, also known as a contingent contract, is a type of agreement where the performance is dependent on an uncertain event. There are several synonyms that can be used to refer to this type of contract, including a chance contract, a gamble contract, a lottery contract, and a risk contract. These terms are all used to describe the unpredictable nature of the performance obligations, as well as the fact that the outcome is largely determined by chance or luck. While aleatory contracts are used in a variety of industries, they are most commonly associated with insurance policies and gambling.