The illegality defense, and may be extended to

ex turpi causa non oritur actio is a legal principle founded in the English
common law stating that an individual or organization who knowingly participate
in illegalities cannot claim damages emanating from the activity. The maxim
applies to tort, trust, property, restitution, and contract laws. The statutory
duty of care presupposes that a plaintiff suing in negligence must base his or
her action upon the common law as the origin of the duty believed to have been
breached. When handling a case of negligence, the courts often consider where
the parties were at the material time, and whether their undertaking was legal.
In case they were engaging in an illegality and negligence was closely related
to the illegal venture, the basic rule eliminating the duty of care will be
applied unless the plaintiff can successfully prove and argue that the
situation formed one of the recognized exceptions. When ex turpi causa is
applied, it deters the complainant from accessing damages1.  Ex turpi causa is often considered as an
illegality defense, and may be extended to immoral conduct.

            The defense of ex turpi causa non
oritur actio could defeat a tortious claim if both parties were engaged in
illegality. For example, in the case of Ashton v Turner and Anr., the plaintiff
was injured when the defendant, who was driving, crashed the car2.
The incident occurred after both individuals had committed a burglary. The offender
had been drinking and was driving negligently in a bid to escape. When the
matter was brought to the court, Ewbank J. dismissed it. He claimed that
because of the public policy, the law would not recognise the supposed duty of
care owed to the claimant because they were participating in an illegal
venture. Ewbank further held that although the duty of care was owed, the
plaintiff had willingly accepted the risk of negligence and the resultant

            Apart from illegality, the maxim defeats
a tortious claim when the underlying action or undertaking is against public
policy. Notably, the policy in question is not grounded on a single reasoning,
but a collection of reasons from different situations. From the perspective of
public policy, the adage of ex turpi causa no oritur actio often defeat a
tortious claim because it is morally wrong for a lawless individual to take
advantage of his crime. Nonetheless, the thinking is hard to apply when in a
tort law where the petitioner is seeking recompense for loss instead of desiring
to make a gain. Some individuals have claimed that such an action should not be
enforced in a contemporary law of tort. Because of the arguments, some
principles have been formulated to guide the application of the maxim. Some of
the principles include the reliance test, inextricably linked, no benefit
principle, proportionality text, the public conscience test, and statutory

            The reliance test, in regards to the
ex turpi causa, considers whether the petitioner has to plead the illicitness.
The test, which is also known as the Bowmakers principle, directs that where
the plaintiff has to plead illegality for the claim, action against the respondent
will not succeed. Under such a circumstance, the maxim will defeat a tortious
claim. Nonetheless, where the plaintiff does not have to plead the illegality,
action against the defendant may succeed. The situation was witnessed in the
Bowmakers Ltd v Barnet Instruments of 19453.
In the case, the offender hired some equipment from the complainant through a
hire purchase arrangement. The applied hire purchase plan did not adhere to the
legislative standards. When the defendant missed payments, the plaintiff wanted
to recover the device. However, the accused argued that the claimant had
engaged in an illegality by failing to adhere to the statutory requirements.
The plaintiff was successful because it did not plead the illegal contract
underlying the claim. The claim was based on ownership of the machine, and
thus, reliance on the illegality could not be introduced.

            The maxim can also defeat a tortious
claim in an inextricably linked principle. Under the principle, it is
not mandatory for the accuser to claim illegality. In the case of Cross v
Kirkby, the accuser was a hunt vandal4. The
defendant was a landowner who got into an altercation with claimant when he
forcibly removed the claimant’s girlfriend from his land. In response, the
claimant attacked the landowner. However, he was injured after being struck on
the head, leading to a skull fracture and subsequently epileptic attacks. Judge
LJ held that his claim was not liable to be conquered ex turpi causa unless it
could be proven that the underlying facts were inextricably associated with his
criminal conduct.

            The maxim can defeat a tortious
claim when the public conscience test principle is applied. The principle is
used to inform whether the conditions of the case will be an insult to the
public conscience to permit the claimant to succeed. When applying the principle,
the jury will consider whether permitting recovery will encourage or deter
criminal behavior. The principle was used in the Thackwell v Barclays Bank Plc.
in 19865.
In the case, the plaintiff sued the bank for exchange of a cheque and
negligence. Barclays Bank raised the ex turpia causa because they believed the plaintiff’s
cheque was part of a fraudulent plan, which he was aware. Because the plaintiff
was aware of the fraudulent act, his action was unsuccessful.

            Based on the statutory influence
principle, the maxim can defeat a tortious action. In many instances, courts
have been influenced by statutory policy goals. For instance, in the case of
Revill v Newberry, it was applied because the 1984 Occupiers Liability Act
safeguarded non-visitors6.
Thus, it was assumed that the parliament never meant to disqualify recovery to
intruders who suffered injury. Under such a circumstance, intruders could not
successfully make tortious claims.

            The maxim also defeats tortious
claims where the plaintiff is in police custody and attempts suicide or
sustains injuries while trying to escape. Concerning attempted suicide in the
custody of law enforcement agency, the defense will not be successful because
it is an immoral act. In the case of Kirkham v Chief Constable of the Greater
Manchester Police, the defense failed because the complainant was of unsound
mind. Ex turpi can prevent a claimant from recovering in a circumstance where
injuries are sustained when attempting to escape from prison. The maxim
defeated a tortious claim in the case of Vellino v Chief Constable of Greater

            Where a petitioner commits a crime
and asserts that the act could not have occurred if the respondent had not been
careless, the issue of whether the individual can recover from loss of liberty
arises. In the case of Meah v McCreamer, it was ruled that a petitioner under
such a circumstance could recover damages7.
However, in the cases of Clunis v Camden and Islington Health Authority and Warrall
v British Railways Board, the Court of Appeal ruled that the public policy
prohibited recovery8. The maxim also defeats a
tortious claim in the case of a joint criminal enterprise. Any party to a joint
criminal enterprise cannot recover in the event of a tortious occurrence. The
principle was demonstrated in the case of Colburn v Patmore of 18349.


            The law concerning the ex turpi
causa non oritur actio is sufficiently clear because it has been developed for
at least two centuries. Over the years, many legal experts have analyzed its
applications and developed numerous principles that could inform users in the
courts. The circumstances where the maxim can be introduced in the court have
been clearly outlined. Besides, judges can refer to hundreds of cases, rulings,
and reasoning that have been used over the years. The principles that have been
formulated, which include statutory influence, the public conscience test,
proportionality test, no benefit principle, inextricably linked, and reliance
test plays an instrumental role in informing the jury’s reasoning and decisions10.
Besides, other circumstances where ex turpia causa can be applied have been
listed. The circumstances include suicide, injuries emanating from escape from
custody, damages for loss of liberty, and joint criminal enterprises.

            Apart from the principles and
circumstances, the law is also applied based on various policies, which
enhances its clarity. The policies underlying the ex turpi causa non oritur
actio law include consistency, deterrence, and the need to preserve the uprightness
of the legal system. The policies also include prevention of profiting from
illegality and the need to further the intent of the rule infringed through
illegal conduct. When reaching a decision, the jury often exercises a careful
balance between achieving just result and the strength of the policies. The
court also takes into account the proportionality of rejecting the claim and
the comparative merits of the parties. The court is required to make a clear
justification whenever an illegality defense is successful.

            Because the law is too broad, it
paves the way for lack of clarity, especially when new cases emerge. For
instance, treatment of third-party liability under the ex turpi causa non
oritur actio is not clear and may result in passing the buck. The application
of ex turpia causa in the fields of insurance and indemnities is still
underdeveloped. Some grey areas concerning the treatment of third parties in
the event of a damaging occurrence remain. Recent cases indicate that in some situations,
third parties can be held responsible for another’s criminal penalty11. For
example, if an insurance broker negligently assures a driver that he is
covered, in the event of fine arising from driving without insurance, the
driver can recover the amount from the service provider. When it can be proven
that a third party played a role in the case, the individual or organization
can be held liable. Application of the maxim in professional indemnity cases is
difficult because of certain self-limiting reasons. For instance, a trader
provides full information and requests an accountant to prepare accounts and
produce correct information. However, the accountant may negligently fail to
provide correct information, making the trader vulnerable to fines. When such a
case is tabled before a civil court, it may be difficult to prove the
defendant’s negligence.

W. V. Horton Rogers, “Ex Turpi Causa Non Oritur Actio,” Liber Amicorum Pierre Widmer,
2003, 16, doi:10.1007/978-3-7091-6094-7_18.

Ashton v Turner and Anr. 1981 l QB

Bowmakers Ltd v Barnet Instruments Ltd 1945 KB 65

Cross v Kirkby 2000 EWCA Civ 426 (AC)

Thackwell v Barclays Bank Plc 1986 1 All ER 676

Revill v Newbery 1996 2 WLR 239

Meah v McCreamer (No. 2) 1986 1 All ER 943

Chris Turner, Key Cases
(Hoboken: Taylor and Francis, 2013), 36.

Colburn v Patmore 1834 Exch 1 CM & R 73

Horton Rogers, “ex turpi,” 88.

Philip Osborne, The Law of
Torts, Second Edition (Toronto: Irwin Law, 2015), 58.