Hardship clause is a clause in a contract that is intended to cover cases in which unforeseen events occur that fundamentally alter the equilibrium of a contract resulting in an excessive burden being placed on one of the parties involved.
The hardship clause is sometimes used in relation to force majeure, particularly because they share similar features and they both cater to situations of changed circumstances.
The difference between the two concepts is that hardship is the performance of the disadvantaged party becoming much more burdensome but still possible.
Force majeure refers to a party's contractual requirements have become impossible, at least temporarily.
Force majeure, however, is situated in the context of nonperformance and deals with the suspension or termination of the contract.