An insurance contract requiring no negotiation or alteration by the insured is categorized as a(n):

A contract characterized by the absence of negotiation or modification by the insured is known as a contract of adhesion. This type of agreement is drafted solely by one party, typically the insurer, and presented to the insured on a take-it-or-leave-it basis. The insured does not have the ability to negotiate the terms and conditions of the contract; they can only accept it as presented or reject it entirely.

In the context of insurance, this means that the insurer has the upper hand in determining the contract's terms, which often leads to favoring the insurer's interests. The principle behind contracts of adhesion is that the party with more power should provide a clearer understanding of the stipulations and obligations involved, given that the other party has limited or no capacity to negotiate or alter those terms.

The other types of contracts listed do not fit this definition. While a standard contract might imply some level of uniformity in terms, it doesn’t exclude the possibility of negotiation. A consensus contract typically requires agreement from both parties and suggests some form of negotiation or bargaining. A formal contract usually refers to one that is executed with specific legal requirements, such as being written or notarized, and does not inherently denote the lack of negotiation.