Consideration in contract law is the value or benefit given by each party in exchange for the other party’s value or benefit—such as money in exchange for products or services, or mutual promises exchanged.

Consideration is often referred to as the bargained-for exchange in which one consideration is exchanged for another consideration.

A mere promise to do or refrain from doing something that lacks consideration in the form of a value or benefit provided by the other party (a return promise) is not a contract and is generally not enforceable. One exception to this rule may be if one party promises to do or refrain from doing something, and the second party relies on that promise to its detriment (by spending money, for example), the detrimental reliance may create an enforceable contract.

And if the consideration for a contract is so insubstantial that it is worthless, the contract is said to be illusory and is not enforceable.

The existence of consideration is what distinguishes an enforceable contract from a promise to make a gift. Because a gift is a voluntary, gratuitous transfer of property from one person to another—without something of value promised in return—the failure to fulfill a promise to make a gift is not enforceable as a breach of contract, as there is no consideration for the promise to make the gift.

In Wisconsin, as in other states, consideration is a fundamental component of a legally binding contract. Consideration refers to something of value that is exchanged between the parties involved in the contract. It can be money, services, goods, or a promise to do or not to do something. The key aspect is that each party must provide something of value to the other, which is known as the 'bargained-for exchange.' Without consideration, a contract is typically not enforceable. However, there are exceptions, such as when one party relies on the promise of the other to their detriment (promissory estoppel). In such cases, the court may enforce the contract to prevent injustice. Contracts with consideration that is deemed to be illusory or so insignificant as to be worthless may be considered unenforceable because they lack the substance of a true exchange. Lastly, promises to make a gift are not enforceable as contracts in Wisconsin because they lack consideration; a gift is a voluntary transfer without an exchange of value.