The importance of the "force majeure" clause in a contract, particularly one of any length in time, cannot be overstated as it relieves a party from an obligation under the contract (or suspends that obligation). What is permitted to be a "force majeure" event or circumstance can be the source of much controversy in the negotiation of a contract and a party should generally resist any attempt by the other party to include something that should, fundamentally, be at the risk of that other party. For example, in a coal-supply agreement, the mining company may seek to have "geological risk" included as a "force majeure" event; however, the mining company should be doing extensive exploration and analysis of its geological reserves and should not even be negotiating a coal-supply agreement if it cannot take the risk that there may be a geological limit to its coal supply from time to time. The outcome of that negotiation, of course, depends on the relative bargaining power of the parties and there will be cases where "force majeure" clauses can be used by a party effectively to escape liability for bad performance.