What principle dictates the adherence to contract terms?

The principle that dictates adherence to contract terms is known as pacta sunt servanda. This Latin phrase translates to "agreements must be kept," and it signifies the fundamental legal concept that parties to a contract are obligated to fulfill their contractual duties as outlined in their agreement. This principle is foundational to contract law, emphasizing the importance of honoring commitments and providing stability and predictability in legal transactions.

In contrast, the other concepts mentioned do not pertain to the enforcement of contractual terms. Prior appropriation relates to water rights management primarily in areas where water is scarce, focusing on the legal principle that the first user of a water source has the right to continue using that water. Adverse possession involves the acquisition of property rights through continuous and open use of someone else's land without permission for a specified period. In loco parentis refers to the legal responsibility of a person or organization to take on some of the functions and responsibilities of a parent. Each of these terms plays a significant role in their respective areas of law but is not relevant to the principle governing the enforcement of contracts.