General defences are arguments that, even if the prosecution proves all the elements of the offence, the defendant should still be acquitted or have the charge reduced. They apply across a range of offences, rather than being specific to one particular crime. Think of them as the defendant saying: "Yes, I did what you say I did, but I have a lawful reason or excuse."
A full defence, if successful, leads to a complete acquittal. Self-defence, intoxication, and insanity (when it negates mens rea) are examples. A partial defence only reduces the charge. For example, diminished responsibility reduces murder to manslaughter, and loss of control reduces murder to voluntary manslaughter. The defendant is still convicted, but of a less serious offence.
| Defence | Type | Result |
|---|---|---|
| Self-defence | Full | Complete acquittal |
| Defence of another | Full | Complete acquittal |
| Intoxication (specific intent) | Full | Acquittal of specific intent offence |
| Intoxication (basic intent) | NOT a defence | No defence available |
| Insanity | Full or partial | Special verdict or hospital order |
| Automatism | Full | Complete acquittal |
| Duress | Full | Complete acquittal |
| Necessity | Full | Complete acquittal |
| Diminished responsibility | Partial | Murder reduced to manslaughter |
| Loss of control | Partial | Murder reduced to manslaughter |
When you see a criminal law problem question, always ask yourself: does the defendant have a general defence? Even if the prosecution has proved all the elements of the offence, a general defence can still lead to an acquittal. Look for signs of self-defence, intoxication, duress, or other defences in the facts.
Self-defence in English law comes from two sources: the common law and statute. Section 3 of the Criminal Law Act 1967 covers the use of reasonable force in preventing crime or making a lawful arrest. The common law covers the use of reasonable force to defend yourself, another person, or your property. In practice, both sources overlap significantly and the courts apply similar principles to both.
A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large.
Once the defendant raises self-defence as an issue (even by a bare assertion), the prosecution must DISPROVE it beyond reasonable doubt. The defendant does not need to prove that they acted in self-defence. This is a fundamental principle: R v Lobban (1995).
For self-defence to succeed, the defendant must satisfy two requirements. First, they must honestly believe that force was necessary. Second, the force they used must have been reasonable in the circumstances as they believed them to be. The first requirement is subjective (it is about what the defendant genuinely thought), and the second is objective (it is about whether a reasonable person would consider the force proportionate), but the objective test is calibrated to the defendant’s subjective perception of events.
Always structure your self-defence analysis in two stages: (1) Did D honestly believe force was necessary? (subjective test) and (2) Was the force used reasonable in the circumstances as D believed them to be? (objective test based on D’s perception). Missing either limb means the defence fails.
The first requirement asks whether the defendant genuinely believed that the use of force was necessary. This is a purely subjective question — it does not matter whether the belief was reasonable. All that matters is that the defendant honestly held that belief. If the defendant was mistaken about the need for force, but the mistake was genuine, this limb can still be satisfied. Even an irrational or mistaken belief can satisfy this test, as long as it is honestly held.
The defendant saw a man dragging a youth along the street. He believed an assault was taking place and intervened, striking the man. In fact, the man was a plainclothes police officer lawfully arresting the youth. The Court of Appeal held that the jury should have been directed that the test was whether the defendant honestly believed he was using force to prevent a crime or assist a lawful arrest. It did not matter that his belief was mistaken — the question was whether it was genuine.
A police officer shot and killed a suspect whom he believed was about to attack him. The Court of Appeal held that a defendant’s genuine belief, even if mistaken, must be taken into account when assessing whether the force used was reasonable. Lord Griffiths stated: "a man about to be attacked does not have to weigh to a nicety the exact measure of his necessary defensive action."
The defendant claimed she had acted in self-defence against her violent partner. The trial judge had directed the jury that the question was whether a reasonable person would have used force. The Court of Appeal corrected this: the question was whether the DEFENDANT genuinely believed she needed to use force to defend herself. The test is subjective to the defendant, not an objective "reasonable person" test at this stage.
The defendant, who lived on a remote farm, shot and killed a burglar. He had been the victim of repeated burglaries and had become fearful and isolated. The Court of Appeal upheld the conviction but emphasised that the jury must consider the defendant’s characteristics (including any mental illness or condition) when assessing whether the defendant’s belief was genuine. The jury should not apply a "reasonable person" test to this first limb.
There is a limit to the subjective nature of this test. If the defendant’s mistake was caused by voluntary intoxication (drugs or alcohol), the honest belief limb may not be available. A drunken mistake about the need for force does not attract self-defence. The defendant must have been sober enough to form a genuine belief: R v O’Grady (1987), R v Hatton (2005).
The second requirement asks whether the force used was reasonable in the circumstances as the defendant believed them to be. This is an objective test, but it is anchored to the defendant’s subjective perception. The jury does not ask whether the force was objectively reasonable in the ACTUAL circumstances — they ask whether it was reasonable given what the defendant HONESTLY believed the circumstances to be.
The defendant, a soldier, shot and killed a man during a drug deal that turned violent. The Privy Council set out the classic direction on self-defence. The jury must judge the reasonableness of the defendant’s actions in the light of the facts as he honestly believed them to be. The jury must also consider whether the defendant may have acted in a moment of unexpected anguish, and not in cold blood. A person defending themselves cannot be expected to weigh their actions to a fine degree.
The defendant, a publican, ejected a drunken customer who fell and hit his head, dying. The Court of Appeal held that the jury must consider whether the force used was reasonable in the circumstances as the defendant believed them to be. However, if the defendant created the situation that led to the need for force, that is relevant to reasonableness.
If the defendant used force that was excessive — more than was reasonably necessary in the circumstances — then self-defence fails completely for the offence charged. However, the defendant may still be acquitted of a more serious offence and convicted of a lesser one. For example, if the defendant honestly believed force was necessary but used excessive (unreasonable) force, they may be acquitted of murder but convicted of manslaughter.
A soldier at a checkpoint in Northern Ireland shot and killed a joyrider who was driving towards him at speed. The soldier fired three shots, the third of which killed the driver as the car was already passing the checkpoint. The House of Lords held that self-defence was not available for the third shot because at that point the car was moving away and the threat had passed. The defendant was convicted of murder, not manslaughter, because by the time of the fatal shot there was no longer any threat to defend against.
If the defendant honestly believed force was necessary (satisfying the first limb) but used unreasonable force (failing the second limb), the result depends on the charge. For murder, the excessive force may reduce the conviction to manslaughter. But if the force was so excessive that it could not be said to be in self-defence at all, the defence fails entirely. The distinction is fact-sensitive.
English law does NOT impose a duty to retreat. A person who is attacked is entitled to stand their ground and use reasonable force to defend themselves. They are not expected to turn and run away, even if retreat would be possible and safe. However, the fact that the defendant COULD have retreated is relevant to the reasonableness of the force used. If it would have been safe and easy to retreat, using force instead may be harder to justify.
The defendant was a barmaid who threw a glass in the face of a customer who had assaulted her. The judge directed the jury that she should have retreated behind the bar. The Court of Appeal quashed the conviction, holding that there was no general duty to retreat. The question was whether the force used was reasonable in the circumstances as the defendant believed them to be.
The defendant, who had a wooden leg, was attacked in his own home. He grabbed a sword and wounded his attacker. The Court of Appeal confirmed that a person is not required to retreat, especially when attacked in their own home. The defendant was entitled to use reasonable force to defend himself.
In 2013, the government amended the Criminal Justice Act 2008 (via the Crime and Courts Act) to give householders enhanced protection when they use force against intruders. Section 76 creates a special rule for "householder cases" — situations where the defendant uses force in their own dwelling against a trespasser or burglar. The key change is a higher threshold: force is NOT reasonable in a householder case only if it was "grossly disproportionate."
In a householder case, the degree of force used by D is not to be regarded as having been reasonable in the circumstances as D believed them to be if it was grossly disproportionate in those circumstances.
A householder case arises when: (1) the defendant uses force while in a dwelling, (2) the force is used against a trespasser (including a burglar), and (3) the defendant is the occupier of the dwelling or is there with the occupier’s permission. The enhanced protection does NOT apply if the defendant was the initial aggressor, or if the trespasser is someone who normally lives there (e.g. a family member returning home).
The householder provision does NOT give householders a free licence to kill burglars. If a householder shoots a fleeing burglar in the back, or sets a trap that kills someone who is trying to escape, that force could still be found to be grossly disproportionate. The enhanced protection is about ensuring that householders are not prosecuted for acting instinctively under extreme stress.
Battered woman syndrome arises in cases where a woman who has suffered prolonged domestic violence kills her abuser, often at a moment when she is NOT under immediate attack. The traditional self-defence requirements — an imminent threat and an immediate need for force — are difficult to satisfy in these cases because the killing may appear premeditated. The courts have developed an approach that allows expert evidence about the psychological effects of prolonged abuse.
The defendant had suffered years of severe physical and emotional abuse from her husband. One night, while he was sleeping, she poured petrol over him and set him alight, killing him. At her first trial, she was convicted of murder. On appeal, fresh psychiatric evidence was admitted showing that she was suffering from battered woman syndrome. The conviction was reduced to manslaughter on the grounds of diminished responsibility, and a retrial was ordered.
The defendant had suffered years of abuse from her husband. She stabbed him with a knife during an argument. At her first trial, the judge had not allowed expert evidence on battered woman syndrome. On appeal, the Court of Appeal held that expert evidence on the syndrome should have been admitted to explain why the defendant might have perceived a threat even when no immediate physical attack was taking place.
The defendant had been subjected to repeated violence by her partner. During an argument, she stabbed him with a kitchen knife. The Court of Appeal held that the jury should have been directed to consider the cumulative effect of the abuse on her state of mind, rather than focusing solely on the immediate circumstances. The conviction was reduced to manslaughter.
Expert evidence on battered woman syndrome helps the jury understand why a defendant in an abusive relationship may have an honest belief that force was necessary, even when an outsider would not see an imminent threat. The syndrome explains the "slow burn" effect of prolonged abuse and the defendant’s distorted perception of danger.
A person CAN use reasonable force in self-defence against a police officer, but only if the officer is acting unlawfully or using excessive force. If the officer is acting lawfully (e.g. making a lawful arrest), the defendant cannot claim self-defence for resisting. The test is the same: did the defendant honestly believe force was necessary, and was the force used reasonable in the circumstances as the defendant believed them to be?
Police officers attempted to take possession of a vehicle from the defendant. The defendant drove away and the officers jumped onto the car, which then collided with another vehicle. The court held that for police conduct to be lawful, it must be within the scope of their common law or statutory powers. If the police are acting beyond their powers, a citizen may use reasonable force to resist them.
In an exam, do not assume that a defendant can claim self-defence against police simply because the police used force. The starting point is that the police were acting lawfully. You need specific facts to show that the police were acting unlawfully or disproportionately before self-defence can succeed against them.
Step 1: Has D raised self-defence? (even a bare assertion is enough)
Step 2: Did D honestly BELIEVE force was necessary? (subjective test)
→ Ask: What did D genuinely think was happening at the time?
→ Consider: Was D’s belief mistaken? If honest, still counts
→ Exception: If D was voluntarily intoxicated, honest belief may not be available
Step 3: Was the force used REASONABLE in the circumstances as D believed them? (objective test calibrated to D’s perception)
→ Consider: Nature of threat, degree of force, proportionality
→ Consider: Could D have retreated? (no duty, but relevant to reasonableness)
→ Consider: Was D acting in the heat of the moment?
→ If householder case: was force "grossly disproportionate"?
Step 4: Burden of proof — prosecution must DISPROVE self-defence beyond reasonable doubt
Outcome: Both limbs satisfied → ACQUITTAL. Honest belief but excessive force → may reduce charge. Neither limb satisfied → defence fails.
The defence of another person is governed by the same principles as self-defence. The defendant must honestly believe that the other person was in danger and that force was necessary to protect them, and the force used must have been reasonable in the circumstances as the defendant believed them to be. The defendant can intervene to protect any person — a stranger, a family member, or a friend.
The defendant saw a group of men attacking his brother and intervened, using a chair leg as a weapon. He claimed he was defending his brother. The Court of Appeal held that the jury should have been directed to apply the same two-stage test as self-defence: did D honestly believe his brother was in danger, and was the force used reasonable in the circumstances as D believed them to be?
Just as with self-defence, a defendant who is MISTAKEN about the need to defend another can still rely on this defence, as long as the mistake was honestly held. See R v Williams (Gladstone) — the same principle applies whether you are defending yourself or another person.
Intoxication is one of the most frequently examined defences. The rules are complex and the key distinction is between voluntary and involuntary intoxication, and between specific and basic intent offences. Getting these distinctions right is essential for the SQE. The leading authority is DPP v Majewski (1977), which established the fundamental framework.
Voluntary intoxication is where the defendant chose to consume alcohol or drugs. Involuntary intoxication is where the defendant did not know they were consuming an intoxicating substance, or where they took medication with no reason to suspect it would cause intoxication. The legal consequences of these two types are very different.
For voluntary intoxication, the key question is whether the offence is one of specific intent or basic intent. If it is a specific intent offence, intoxication CAN be a defence if the defendant was so intoxicated that they lacked the required mens rea. If it is a basic intent offence, intoxication is NOT a defence — the defendant is judged against the standard of a sober person. This distinction comes from DPP v Majewski.
A specific intent offence requires the defendant to have a particular intention BEYOND the actus reus. There must be a further mental element. For example, murder requires an intention to kill or cause grievous bodily harm — this goes beyond the mere act of causing death. Theft requires an intention to permanently deprive — this goes beyond the mere act of taking.
A basic intent offence is one where the mens rea does NOT go beyond the actus reus. The intention to do the act itself is sufficient. For example, s.47 OAPA (ABH) requires only intention or recklessness as to causing some physical harm — the same intention that forms part of the actus reus. S.20 OAPA (GBH) and s.18 OAPA (GBH with intent) illustrate the difference: s.20 is basic intent, s.18 is specific intent.
| Offence | Intent Type | Can Intoxication Defend? | Notes |
|---|---|---|---|
| Murder | Specific | Yes — if D lacked intent to kill/GBH | May still be convicted of involuntary manslaughter |
| S.18 OAPA (GBH with intent) | Specific | Yes — if D lacked the specific intent | May still be convicted of s.20 or s.47 |
| Attempt | Specific | Yes — if D lacked intent for the full offence | D must have been too intoxicated to form the specific intent |
| Theft | Specific | Yes — if D lacked intent to permanently deprive | R v Kingston: intoxication must negate mens rea |
| Burglary | Specific (entry with intent) | Specific element: yes | The entry itself is basic intent, but the ulterior intent is specific |
| S.47 OAPA (ABH) | Basic | No | D judged against sober standard |
| S.20 OAPA (GBH) | Basic | No | D judged against sober standard |
| Rape | Basic | No | D judged against sober standard |
| Involuntary manslaughter | Basic | No | D judged against sober standard |
| Criminal damage | Basic | No | D judged against sober standard |
| Affray | Basic | No | D judged against sober standard |
Ask yourself: does the offence require an intention that goes BEYOND simply intending to do the act? If yes, it is specific intent. If the mens rea is simply intention or recklessness as to the act itself, it is basic intent. For murder, ask: is intending to kill/GBH something beyond just intending to do the act that caused death? Yes — so it is specific intent.
The defendant, who was heavily under the influence of drugs and alcohol, assaulted several people in a pub and attacked police officers. He was charged with offences including ABH and assault occasioning actual bodily harm (basic intent offences). The House of Lords held that voluntary intoxication is NOT a defence to basic intent offences. For specific intent offences, intoxication CAN be a defence if it prevented the defendant from forming the required specific intent. The rationale is that a person who deliberately intoxicates themselves should not be allowed to rely on their own recklessness as a defence.
For specific intent offences, the question is whether the defendant was so intoxicated that they could not form the required specific intent. If the intoxication was so extreme that the defendant lacked the mens rea for the specific intent offence, they will be acquitted of that offence. However, they may still be convicted of a lesser basic intent offence. For example, if D was too drunk to form the intent for murder, they may be acquitted of murder but convicted of involuntary manslaughter.
The defendant and his co-accused had been drinking heavily. They attacked a man, causing him serious injuries. The trial judge directed the jury that voluntary intoxication was not a defence to the specific intent offence of s.18 OAPA. The Court of Appeal held this was a misdirection — voluntary intoxication IS a potential defence to s.18 if the defendant was too intoxicated to form the specific intent to cause grievous bodily harm. The case was remitted for retrial.
The defendant, who was extremely drunk, set fire to a house. He was charged with arson, which is a basic intent offence. The Court of Appeal confirmed that voluntary intoxication is not a defence to basic intent offences. Even if the defendant was so drunk that he did not appreciate the risk of damage, he is judged by the standard of a sober person. The conviction was upheld.
Even though voluntary intoxication is not a defence to basic intent offences, the jury still needs to consider it. If the defendant was so intoxicated that he did not form the mens rea at all (not even recklessness), should the jury still convict? The answer is that for basic intent offences, the defendant is judged against the standard of a sober person who intended the act. If a sober person would have foreseen the risk, the intoxicated defendant is treated as having been reckless.
The defendants, who were very drunk, set fire to a ship in which they were sleeping. They claimed they were too intoxicated to appreciate the risk. The Court of Appeal held that for a basic intent offence, the jury must consider what the defendant would have foreseen if he had been sober. If a sober person in the defendant’s position would have foreseen the risk, the defendant is treated as reckless. The jury must give this direction even though intoxication is not technically a defence.
The "lip service" direction means the judge must MENTION intoxication to the jury in a basic intent case, but the jury will almost always still convict. The practical effect is that intoxication is almost never a defence to basic intent offences. The direction is a formality to ensure fairness, not a genuine defence route.
Involuntary intoxication occurs when the defendant consumed an intoxicating substance without knowing what it was, or without knowing its likely effects. This can happen in several ways: someone spikes the defendant’s drink, the defendant takes medication without knowing its side effects, or the defendant takes a substance that was stronger or different from what they expected.
The defendant was a paedophile who was secretly given a sedative and then a young boy was brought to him. He claimed he was too intoxicated to form the intent for indecent assault. The House of Lords held that involuntary intoxication is only a defence if it negates the mens rea of the offence. If the defendant would have had the necessary mens rea but for the intoxication, the defence fails. Involuntary intoxication is NOT a defence to specific intent offences if the defendant still formed the required intent.
The defendant, who was depressed, took some of his girlfriend’s valium tablets and then set fire to a wardrobe. He claimed he was involuntarily intoxicated because he did not know the valium would make him behave irrationally. The Court of Appeal held that the jury should have been told that if the defendant did not know the drug would have a sedative effect, his intoxication was involuntary. If the defendant did not know the nature or likely effect of the substance, it is involuntary.
For involuntary intoxication to succeed: (1) the intoxication must have been involuntary (the defendant did not know what they were taking, or did not know its effects), and (2) the intoxication must have negated the mens rea of the offence charged. If the defendant still formed the required mens rea despite being involuntarily intoxicated, the defence fails (R v Kingston). If the intoxication negated the mens rea, the defendant is acquitted of that offence.
Unlike voluntary intoxication, involuntary intoxication CAN be a defence to basic intent offences. If the defendant was involuntarily intoxicated and could not form the mens rea (even recklessness) for a basic intent offence, they should be acquitted. The "sober person" standard does NOT apply to involuntary intoxication.
| Scenario | Specific Intent Offence | Basic Intent Offence |
|---|---|---|
| Voluntary intoxication | Defence if D lacked specific intent | NOT a defence — judged by sober standard |
| Voluntary intoxication (extreme) | Acquittal of specific offence; may face lesser charge | Conviction still possible |
| Involuntary intoxication | Defence if it negated mens rea | Defence if it negated mens rea |
| Spiked drink | Treat as involuntary intoxication | Treat as involuntary intoxication |
| Medication (unexpected effects) | Treat as involuntary intoxication | Treat as involuntary intoxication |
| "Lip service" direction | Not required | Required — jury must consider sober standard |
When answering a question on intoxication: (1) Identify whether the intoxication was voluntary or involuntary. (2) Identify whether the offence is specific or basic intent. (3) Apply the relevant rule. (4) Consider whether a lesser offence is available. (5) If basic intent, mention the "lip service" direction. This structured approach will ensure you hit all the marks.