Insurance contracts have unique characteristics, one of which is that they are:

Insurance contracts are indeed classified as contracts of adhesion. This designation refers to the nature of how such contracts are created and agreed upon. In a contract of adhesion, one party typically drafts the terms and conditions, while the other party has limited or no ability to negotiate these terms. The party creating the contract, which is usually the insurer, has more power in determining the specifics of the contract, while the insured must accept the contract as it is or forgo insurance altogether.

This characteristic is significant because it impacts how disputes are resolved. Courts often interpret ambiguous terms in insurance contracts against the interests of the insurer, as they are the ones who authored the contract. This principle serves to protect consumers who may not have the legal or professional knowledge to understand all terms fully.

The other options provided do not accurately capture the essence of insurance contracts. For instance, while insurance agreements may be written, they are not exclusively limited to written formats, as some might also be verbal in certain contexts. Similarly, contracts in insurance do not typically remain in perpetuity, as they generally have defined terms and conditions with an expiration or renewal process. Lastly, the negotiation aspect does not apply here, since the nature of these contracts favors adhesion rather than active negotiation by both parties.