The force majeure event must cause "extreme and unreasonable difficulty, expense, injury, or loss. " A mere increase in expense does not excuse performance.Under California law, unless a contract explicitly identifies an event as a force majeure the event must be unforeseeable at the time of contracting to qualify. A. Force Majeure events include, but are not limited to: (1) catastrophic acts of nature, or public enemy;. Force majeure refers to any event or circumstances that stop a party from fulfilling its obligations and which (crucially) are outside the party's control.