SQE1 criminal defences: what you must know and how it is tested

SQE1 criminal defences questions test self-defence, duress, intoxication, insanity and automatism. For each, know when it applies, which offences it covers and who carries the burden. Read it with the wider Criminal Liability guide.

The rules to apply

Self-defence is a complete defence. Force must be necessary and reasonable in the circumstances as the defendant honestly believed them to be (Criminal Justice and Immigration Act 2008, s76). An honest mistaken belief counts even if unreasonable, but not if it was caused by voluntary intoxication (R v O'Grady). In householder cases, force that was disproportionate but not grossly disproportionate may still be reasonable. A defendant is not expected to weigh the force exactly in the heat of the moment. The prosecution must disprove it once raised.

Duress by threats requires a threat of death or serious injury, and the reasonable person of reasonable firmness would have acted in the same way. The defendant must not have voluntarily joined a criminal group which could make such threats (R v Hasan). It is not available for murder (R v Howe) or attempted murder (R v Gotts). Duress of circumstances applies to threats from circumstances (R v Willer). Necessity is very limited.

Intoxication. Voluntary intoxication is no defence to basic intent crimes (DPP v Majewski), such as assault, but can negate the mens rea of specific intent crimes (such as murder or theft) if the defendant did not form it. Dutch courage gives no defence. Involuntary intoxication only helps if the defendant did not form the mens rea (R v Kingston).

Insanity (M'Naghten rules): a defect of reason from a disease of the mind meant the defendant did not know the nature and quality of the act, or that it was wrong. The special verdict is not guilty by reason of insanity, and the defendant bears the burden. Automatism is a complete loss of voluntary control due to an external factor, giving a full acquittal if not self induced. A cause that is internal, such as epilepsy or a sleepwalking disorder, is treated as insanity (R v Sullivan; R v Burgess).

Traps examiners use

• Allowing a mistaken belief induced by voluntary intoxication to support self-defence.
• Offering duress as a defence to murder.
• Applying Majewski to specific intent offences.
• Treating an internal cause such as epilepsy as non-insane automatism.
• Putting the burden for self-defence on the defendant.

Worked question 1

Mal, who is drunk, wrongly believes Vik is about to attack him with a knife. Vik was holding a phone. Mal punches Vik and is charged with assault occasioning actual bodily harm, a basic intent crime. Mal relies on self-defence. Which is correct?

• A. Self-defence succeeds, because Mal honestly believed he was in danger.
• B. Self-defence fails, because the mistaken belief was caused by voluntary intoxication.
• C. Self-defence succeeds, because intoxication is a defence to every offence.
• D. Self-defence fails, because the belief was unreasonable.
• E. Self-defence succeeds, because drunkenness is involuntary.

Answer: B. An honest belief need not be reasonable (D is wrong), but a belief caused by voluntary intoxication cannot found self-defence (R v O'Grady). A ignores the O'Grady rule and C overstates Majewski.

Worked question 2

Tor is threatened by a gang with death unless he kills Pam. He kills her. At his murder trial he relies on duress. What is the likely result?

• A. Duress succeeds if a person of reasonable firmness would have acted the same way.
• B. Duress is not available as a defence to murder.
• C. Duress reduces the offence to manslaughter.
• D. Duress succeeds if the threat was imminent.
• E. Duress succeeds because he did not intend to kill.

Answer: B. R v Howe holds that duress is not a defence to murder, whoever commits it. It does not reduce it to manslaughter either. A would apply to other offences. D and E misstate the law.

Checklist before you move on

• Is it a complete or a partial defence?
• Self-defence: honest belief, necessity, reasonableness.
• Duress: threat, firmness, no voluntary association, not murder.
• Intoxication: voluntary or involuntary, specific or basic intent?
• Insanity or automatism: internal or external cause?
• Who bears the burden?

Test yourself on more original questions in our SQE1 practice questions.

Questions

Related

• SQE1 Criminal Liability
• SQE1 practice questions: how to answer single best answer items
• SQE1 mock: how to time, pace and review it

Sources: SRA: SQE1 Assessment Specification (from 1 September 2026); Criminal Justice and Immigration Act 2008, section 76; Find Case Law (National Archives). Checked 10 November 2026.