What is the term for a contract offered on a take-it-or-leave-it basis, with no negotiation allowed?

The term that describes a contract offered on a take-it-or-leave-it basis, with no room for negotiation, is known as a Contract of Adhesion. This type of contract is typically created by one party, often in a position of power, and presented to the other party on a standard form. The accepting party does not have the opportunity to negotiate the terms; they must either accept the contract as it stands or reject it entirely.

Contracts of Adhesion are commonly found in various agreements, such as insurance policies or service contracts, where the provider sets the terms, and the consumer is expected to agree to them without any modifications. This characteristic is what differentiates them from other types of contracts, where negotiation is an integral part of the agreement process.

In contrast, a mutual contract involves negotiation and agreement on terms by both parties, making it a collaborative process. A unilateral contract involves a promise made by one party in exchange for a performance by another party, without the necessity for a reciprocal promise. An onerous contract includes obligations for both parties, typically requiring a benefit or a burden from each side. Thus, the defining feature of a Contract of Adhesion is its non-negotiable nature, which makes it the correct answer.