This note outlines the use of force majeure clauses. It explains the meaning of the force majeure concept and the rationale for the use of force majeure clauses. It covers the main elements of a typical force majeure clause, including how force majeure events are defined, the need for causation and the relief that is provided. The note examines the types of force majeure events that most commonly raise issues for the parties, including strikes, subcontractor or supplier default, acts of government, acts of God and pre-existing events. It also covers the affected party's obligations to notify the other party and take reasonable steps to mitigate the effect of a force majeure event, factors to consider when relying on a force majeure clause and where legislation may limit the use of a force majeure clause.