Which feature commonly indicates a voidable contract?

A feature that commonly indicates a voidable contract is a lack of capacity. Contracts may be voidable when one of the parties does not have the legal ability to enter into a contract. This situation often arises in cases involving minors, individuals who are mentally incapacitated, or intoxicated persons. Such parties may have the right to affirm or void the contract, depending on their circumstances.

Mutual assent refers to the agreement between parties on the contract terms, which is a fundamental element of a valid contract rather than a factor that renders a contract voidable. Legality of purpose ensures that the contract's objective complies with the law; if the purpose is illegal, it cannot form a valid contract at all. A written form requirement pertains to certain types of contracts that must be in writing to be enforceable, but this is not directly related to the concept of voidability. Thus, the presence of a lack of capacity is the defining feature that can render a contract voidable.