Contract – force majeure

Q.
What is 'Force Majeure' in contract law?
A.
Force Majeure or vis major (Latin) "superior force", is also known as cas fortuit (French) or casus fortuitus (Latin) "chance occurrence, unavoidable accident",[1] 

Force majeure is a common clause in contracts that essentially frees both parties from liability or obligation when an extraordinary event or circumstance beyond the control of the parties, such as a war, strike, riot, crime, or an event described by the legal term act of God (such as hurricane, flooding, earthquake, volcanic eruption, etc.), prevents one or both parties from fulfilling their obligations under the contract. In practice, most force majeure clauses do not excuse a party's non-performance entirely, but only suspends it for the duration of the force majeure.[2][3]

Force majeure is generally intended to include risks beyond the reasonable control of a party, incurred not as a product or result of the negligence or malfeasance of a party, which have a materially adverse effect on the ability of such party to perform its obligations,[4] as where non-performance is caused by the usual and natural consequences of external forces (for example, predicted rain stops an outdoor event), or where the intervening circumstances are specifically contemplated.

Force Majeure is not to be confused with Quantum Meruit.

Force Majeure can give rise to Quantum Meruit, for example a contract about organizing a concert with Shila The Singer was affected by heavy rainfall from the evening. The concert was cut short to half the original plan.

In such circumstances, the act of GOD - heavy rain is Force Majeure, and due to such condition, the contract was performed only half. The quantum of payment would be Quantum Meruit, to compensate half the original sum.
Ref:
http://en.wikipedia.org/wiki/Force_majeure
https://en.m.wikipedia.org/wiki/Quantum_meruit