Civil Code § 1569

Duress consists in any of the following:

(a) Unlawful confinement of the person of the party, or of the spouse of such party, or of an ancestor, descendant, or adopted child of such party or spouse.

(b) Unlawful detention of the property of any such person.

(c) Confinement of such person, lawful in form, but fraudulently obtained, or fraudulently made unjustly harassing or oppressive.