Ex turpi causa non oritur actio meaning

A principle allowing courts to refuse a civil claim where it is founded on the claimant’s own illegal or seriously wrongful conduct (the illegality defence). Judge-made and developed in case law, it is invoked across contract, tort/delict, unjust enrichment and trust disputes. The bar applies only where there is a sufficiently close connection between the illegality and the claim. In England & Wales and Northern Ireland, following Patel v Mirza, courts weigh: the purpose of the law breached; relevant public policies (including the integrity of the legal system); and whether denying relief is proportionate. Remedies affected include damages, contribution, enforcement of contracts, restitution and proprietary relief. A claimant cannot rely on their criminality to found a cause of action, but illegality does not automatically defeat a claim. In Scotland, the principle is applied similarly within delict and unjustified enrichment, guided by UK Supreme Court authority. In Ireland, a comparable public-policy illegality doctrine operates in case law, with courts assessing the closeness of connection and proportionality. Usage and rationale are broadly consistent across these jurisdictions.