Following up on my previous post, below is a laundry list (in alphabetical order) of affirmative defenses; source: Rule 8(c)(1) of the Federal Rules of Civil Procedure:

• accord and satisfaction

• arbitration and award

• assumption of risk

• contributory negligence

• duress

• estoppel

• failure of consideration

• fraud

• illegality

• injury by fellow servant

• laches

• license

• payment

• release

• res judicata

• statute of frauds

• statute of limitations

• waiver

Hmm. Aside from necessity and mistake (again, see my previous post), what other legal defenses are missing from this list?