This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
Duress, like fraud, misrepresentation, mistake, and non-disclosure, may affect the execution or the inducement. Duress in the execution is rare. It exists where the party subjected thereto is coerced into permitting a contract, written and signed by himself, to be taken from him without intending to deliver it.1 If one signs a check because of an immediate threat to take his life, which will apparently be carried into execution if he does not comply with such demand, he is said to be a mere automaton, and such check as between himself and the payee is void.2 In cases like this, duress is operative only to rebut the inference of voluntary delivery that otherwise would exist. Such form of duress makes the contract void.
Many text writers suggest that duress in the formation may exist in oral contracts where the party subjected to duress is compelled to repeat words which of themselves would constitute a contract, without any intention of being bound thereby. While adjudicated cases on this point are uncommon, the view seems probable, in analogy to contracts made in jest.3