Under what condition can a modification still be valid at common law despite lacking consideration?

A modification of a contract can still be valid at common law without new consideration if it is deemed fair and equitable under the circumstances. This principle allows for adjustments to contractual agreements when unexpected events arise, provided that the modification is just and reasonable based on the situation of the parties involved. The courts may consider factors such as changes in circumstances or hardships that necessitate a modification, showing that fairness is a primary concern in adjudicating disputes related to contract modifications without consideration.

This understanding is rooted in the common law principles that prioritize equity and fairness, especially in situations where strict adherence to the requirements of consideration may lead to unjust outcomes. Thus, even in the absence of new consideration, a modification that meets the criteria of being fair and equitable can still be enforceable.

The other options do not align with common law principles. A modification benefiting only one party without consideration could be deemed one-sided and therefore potentially unenforceable. A verbal modification's validity would depend largely on whether the original contract required written changes, as some contracts must be in writing to be enforceable. Documentation alone does not validate a modification if there is a lack of consideration unless it meets the fairness standard.