Ex Turpi Causa Non Oritur Actio

Ex turpi causa non oritur actio (Latin for "from a dishonorable cause an action does not arise") is a legal doctrine which states that a claimant will be unable to pursue a cause of action if it arises in connection with his own illegal act. Particularly relevant in the law of contract, tort and trusts, ex turpi causa is also known as the "illegality defence", since a defendant may plead that even though, for instance, he broke a contract, conducted himself negligently or broke an equitable duty, nevertheless a claimant by reason of her own illegality cannot sue.