Sections 20 and 18 of the Offences Against the Person Act 1861 are the two most serious non-fatal offences against the person. Section 20 covers unlawfully wounding or inflicting grievous bodily harm, while Section 18 covers wounding or causing grievous bodily harm with intent. The key difference between them is the mens rea: Section 20 requires intention or recklessness as to some physical harm, whereas Section 18 requires a specific intent to wound or cause GBH. This distinction is absolutely critical for your SQE1 exam and for advising clients in practice.
These offences sit in the middle of the hierarchy of non-fatal offences. Below them are common assault and assault occasioning actual bodily harm (Section 47). Above them is murder. In practice, the difference between a Section 20 and a Section 18 charge can mean the difference between a case that stays in the magistrates’ court and one that goes to the Crown Court, and the difference between a maximum of five years and a potential life sentence. You need to understand both offences inside out.
A wound is a break in the continuity of the whole skin. This means both the outer layer (epidermis) and the inner layer (dermis) must be broken. A scratch or a graze that only affects the outer layer is not enough. The classic definition comes from case law and is straightforward in principle but can be tricky on the facts. Internal bleeding does not count as a wound because there is no break in the skin.
In R v JCC, the defendant burst a spot on the victim’s face, causing bleeding. The court held that this was not a wound because there was no break in the continuity of the whole skin. The spot was already a break in the skin surface, so bursting it did not create a new break. This case shows how technical the definition of a wound can be and why you need to pay close attention to the medical evidence.
In R v MBE, the Court of Appeal confirmed that for a wound there must be a break in the continuity of the whole skin (both dermis and epidermis). The case reinforced the established approach and confirmed that the prosecution must prove the full break in skin continuity. This is a useful authority to cite when arguing that an injury does not meet the threshold for a wound.
Grievous bodily harm means really serious bodily harm. It is the more serious alternative to a wound and does not require any break in the skin. GBH can include broken bones, deep lacerations, serious bruising, organ damage, and even serious psychiatric injury. The question of how serious the harm must be is fact-sensitive and depends on the individual victim.
In R v Duggan, the defendant kicked the victim in the head, causing bruising and swelling. The court held that this amounted to GBH. The harm was classified as really serious because of its location on the head and the potential for long-term consequences. This case reminds you that you should not focus only on the immediate injury but also on the seriousness of the body part affected and the potential consequences.
In R v Bollom, the defendant assaulted a 17-month-old baby, causing bruising and a fractured arm. The trial judge had directed the jury that GBH must be serious in the context of a normal, healthy adult. The Court of Appeal disagreed and held that the jury should consider the seriousness of the harm in the context of the particular victim. The same injury that is relatively minor to a fit adult could be GBH to a baby or an elderly person. This context-dependent approach is important to remember.
When analysing a problem question, ask yourself: was the skin broken in its entirety? If yes, you have a wound. If not, is the harm really serious? If yes, you may have GBH. Both satisfy the actus reus for s.20 and s.18. You do not need both — either one is sufficient.
Whosoever shall unlawfully and maliciously wound or inflict any grievous bodily harm upon any other person, either with or without any weapon or instrument, shall be guilty of an offence.
The actus reus of Section 20 has two elements. First, the defendant must cause a wound or GBH to the victim. Second, the wounding or infliction of harm must be unlawful and malicious. Unlawful means without lawful excuse (such as consent in certain situations or self-defence). Maliciously simply means intentional or reckless — it does not require any hostility or ill will towards the victim. These terms can be confusing but they have settled meanings in case law.
The word "inflicts" in Section 20 has been interpreted broadly by the courts. It does not require direct physical contact between the defendant and the victim. The defendant can inflict harm by setting in motion a chain of events that results in the injury. This is wider than the word "causes" used in Section 18, though in practice both have been given a wide meaning. The key point is that the defendant’s act must be a substantial and operating cause of the harm.
In R v Lewis, the defendant drove his car at a police officer. The officer jumped out of the way but injured himself when landing. The court held that the defendant had "inflicted" the injury even though he never made physical contact with the officer. The defendant’s dangerous driving caused the officer to take evasive action, which led to the injury. This case shows how broadly "inflicting" is interpreted.
In R v Martin, the defendant set a trap in his shop that fired a spring gun when the door was opened. A burglar triggered the trap and was injured. The court held that the defendant had inflicted the harm even though he was not present at the time. His act of setting the trap was a continuing act that caused the injury when the trap was triggered. This confirms that indirect causation is sufficient for Section 20.
Yes. The courts have confirmed that serious psychiatric injury can amount to grievous bodily harm for the purposes of both Section 20 and Section 18. This is important because it means that a defendant who causes severe mental harm through a campaign of harassment or intimidation can be charged with these offences even if there is no physical injury at all. However, the psychiatric harm must be recognised as a medical condition, not just ordinary distress or anxiety.
In R v Ireland, the defendant made repeated silent telephone calls to women. The victims suffered severe psychological trauma including anxiety, depression, and sleep disturbance. The House of Lords held that this could constitute an assault occasioning actual bodily harm, and by extension, serious psychiatric injury could amount to GBH. The case is primarily about ABH but established the principle that psychiatric injury is capable of being really serious harm.
In R v Constanza, the defendant pursued a campaign of harassment against a woman, including following her, writing her letters, and threatening her. She suffered severe depression and panic attacks. The court held that psychiatric injury could amount to actual bodily harm and, if serious enough, grievous bodily harm. The case also confirmed that words alone can constitute an assault. Together with Ireland, this case makes clear that psychiatric injury is a real and recognised form of bodily harm under the OAPA.
Ordinary emotions such as fear, distress, or embarrassment are not enough. The psychiatric harm must be a recognised medical condition, such as post-traumatic stress disorder, severe depression, or an anxiety disorder. You will need expert medical evidence to prove that the harm is both real and serious enough to amount to GBH.
The mens rea for Section 20 is intention or subjective recklessness as to some physical harm. Crucially, the defendant does not need to intend or foresee a wound or GBH specifically. They only need to intend or foresee some physical harm, however minor. If they punch someone intending or being reckless as to causing a bruise, and the victim falls and sustains a serious head injury, the defendant is guilty of Section 20 because the mens rea is satisfied by the intention to cause some harm.
In R v Mowatt, the defendant attacked the victim from behind and beat him severely, causing serious injuries. The defendant claimed he only intended to rob the victim and did not intend serious harm. The Court of Appeal held that it was not necessary for the prosecution to prove that the defendant intended or foresaw the actual harm caused. It was sufficient to prove that the defendant intended or was reckless as to some physical harm. This is the leading authority on the mens rea of Section 20.
These joined cases confirmed the position from Mowatt. In Savage, the defendant threw a glass in a pub which hit another woman and caused a small cut. In Parmenter, the defendant had a habit of throwing his baby in the air and catching him, but on one occasion dropped him, causing serious injuries. The House of Lords held that for Section 20, the prosecution only needs to prove that the defendant intended or was reckless as to some physical harm. Neither case required foresight of wounding or GBH. Parmenter is also important because the defendant was convicted of Section 20 but acquitted of Section 18 — the factual matrix is worth knowing.
R v G and Another is the leading modern authority on recklessness in criminal law generally. The House of Lords overruled the objective test of recklessness from Caldwell and restored the purely subjective test. A person is reckless if they consciously take an unjustified risk of some harm occurring. They must actually realise the risk at the time of the act. A reasonable person test does not apply. This case applies to Section 20: the defendant must have subjectively foreseen the risk of some physical harm.
For Section 20, the prosecution only needs to prove that the defendant intended or foresaw some physical harm. The defendant might have only intended a minor bruise, but if the actual injury is GBH, they are still guilty of Section 20. This is why Section 20 is sometimes described as a crime of "resulting harm" — the harm that results can be far more serious than the harm the defendant had in mind.
Section 20 is triable either way, meaning it can be heard in the magistrates’ court or the Crown Court. The maximum sentence is five years’ imprisonment. In the magistrates’ court, the sentencing powers are limited to six months’ imprisonment. In practice, serious Section 20 offences will almost always be sent to the Crown Court for sentence. The sentencing guidelines recommend a starting point of around two years’ custody for a single punch causing serious injury, rising for more serious cases involving weapons or sustained attacks.
Whosoever shall unlawfully and maliciously by any means whatsoever wound or cause any grievous bodily harm to any person, with intent to do some grievous bodily harm to any person, or with intent to resist or prevent the lawful apprehension or detainer of any person, shall be guilty of an offence.
The actus reus of Section 18 is the same as Section 20: the defendant must cause a wound or GBH to the victim. The difference is that Section 18 uses the word "cause" rather than "inflict", but in practice the courts have not drawn a meaningful distinction between these two words for the purposes of the actus reus. The wound or GBH must still be unlawful and malicious. If the defendant’s actions cause a wound or GBH, the actus reus is made out.
This is where Section 18 is fundamentally different from Section 20. The mens rea of Section 18 requires a specific intent to do some grievous bodily harm to any person. Recklessness is not enough. The defendant must actually intend to cause really serious harm. They do not need to intend the specific harm that actually occurred, but they must have intended some GBH. This is a much higher threshold than Section 20 and makes Section 18 a specific intent offence.
The intent required for Section 18 can be either direct or oblique. Direct intent means the defendant’s purpose or aim was to cause GBH. Oblique intent means the defendant did not desire GBH but knew it was virtually certain to result from their actions. Both forms of intent satisfy the mens rea of Section 18. This follows the approach in R v Woollin for murder and has been applied to Section 18 by analogy.
In R v Belfon, the defendant was involved in a fight and used a broken bottle. He argued that he had not intended to cause GBH. The Court of Appeal held that for Section 18, the jury must be sure that the defendant intended to cause really serious bodily harm. If the defendant only intended to cause some harm (but not GBH), then the correct verdict was Section 20, not Section 18. This case clearly establishes the distinction: foresight of some harm is Section 20, intention of GBH is Section 18.
In R v Powell and English, the House of Lords considered the mens rea of Section 18 in a joint enterprise context. The court confirmed that for a secondary party to be guilty of Section 18, they must have realised that the principal might intentionally cause GBH and intentionally assisted or encouraged that. If the secondary party only foresaw the possibility of some harm (but not the intentional infliction of GBH), they could be guilty of Section 20 but not Section 18. The case reinforces the high mens rea threshold for Section 18.
Section 18 also covers wounding or causing GBH with intent to resist or prevent the lawful apprehension or detainer of any person. This alternative mens rea applies where the defendant wounds or causes GBH in order to escape from the police or to help someone else escape. The intent is not to cause GBH but to resist arrest — the GBH is the means to that end. If the prosecution cannot prove intent to cause GBH but can prove intent to resist apprehension, the defendant can still be convicted of Section 18.
Section 18 is an indictable-only offence, meaning it must be tried in the Crown Court. The maximum sentence is life imprisonment. In practice, sentences for Section 18 vary enormously depending on the circumstances. The sentencing guidelines provide starting points ranging from around six years for a single blow causing serious injury to much longer sentences for attacks involving weapons, premeditation, or sustained violence. A custodial sentence is almost inevitable for a Section 18 conviction.
| Feature | Section 20 | Section 18 |
|---|---|---|
| Description | Unlawful wounding or inflicting GBH | Wounding or causing GBH with intent |
| Actus reus | Wound or GBH | Wound or GBH (same as s.20) |
| Mens rea | Intention or recklessness as to SOME physical harm | INTENTION to cause GBH (specific intent) |
| Recklessness sufficient? | Yes | No |
| Type of offence | Basic intent | Specific intent |
| Triable | Either way | Indictable only |
| Court | Magistrates’ or Crown Court | Crown Court only |
| Maximum sentence | 5 years’ imprisonment | Life imprisonment |
| Alternative mens rea | None | Intent to resist/prevent lawful apprehension |
If you remember one thing about s.20 and s.18, remember this: the ONLY difference is the mens rea. The actus reus is the same. If the defendant intended or was reckless as to some physical harm, that is s.20. If the defendant intended to cause GBH, that is s.18. Recklessness can never satisfy s.18.
Transferred malice applies when a defendant intends to harm one person but accidentally harms another instead. The defendant’s mens rea transfers from the intended victim to the actual victim. So if A intends to cause GBH to B but misses and hits C instead, A’s intent transfers to C and A is guilty of Section 18 against C. The doctrine ensures that the defendant cannot escape liability simply because they were a poor shot or made a mistake about their target.
In R v Latimer, the defendant aimed a blow at one man with his belt but the belt slipped and hit a woman standing nearby, causing a cut on her head. The court held that the defendant’s intent transferred from the intended victim to the actual victim. He was guilty of the offence against the woman even though she was not his target. This is the classic authority for transferred malice and applies equally to Section 20 and Section 18.
In R v Mitchell, the defendant tried to rob an elderly man in a post office queue. The man had a heart attack and collapsed onto an elderly woman, who also died. The court held that transferred malice could not apply here. The defendant’s intent was to harm the man, but the woman’s death was not a direct result of the defendant’s act against the man — it was caused by the man falling on her. Transferred malice only operates where the harm to the unintended victim is a direct consequence of the defendant’s act against the intended victim.
Transferred malice only works if the mens rea and the actus reus are of the same type. You cannot transfer the intent to cause GBH to a murder charge (a different offence). And if the chain between the defendant’s act and the harm to the unintended victim is too indirect, transferred malice may not apply, as Mitchell shows. Always check whether the harm to the actual victim was a direct result of the defendant’s actions towards the intended victim.
As with all criminal offences, the prosecution must prove that the defendant’s act caused the wound or GBH. The usual test is the "but for" test: but for the defendant’s actions, would the harm have occurred? If the answer is no, the defendant is the cause. Even if there are other contributing factors, the defendant’s act must be a substantial and operating cause of the harm. The chain of causation can be broken by intervening events.
In R v Cheshire, the defendant shot the victim in the thigh and stomach. The victim underwent surgery but developed breathing difficulties. The doctors failed to treat this properly and the victim died. The Court of Appeal held that the defendant’s act was still the cause of death because the original injury was the operating and substantial cause. Mere incompetence or negligence in medical treatment will not break the chain of causation. Only if the medical treatment is so independent and irresponsible that it makes the original injury insignificant will the chain be broken.
In R v Malcherek, the defendant stabbed his wife. She was put on a life support machine and declared brain dead. The doctors turned off the machine and she died. The defendant argued that the doctors switching off the machine broke the chain of causation. The House of Lords held that it did not. The original stabbing was the cause of death and the doctors’ decision to turn off the machine was not a novus actus interveniens (a new intervening act). This case is important because it shows that medical decisions, even ones that end life support, do not necessarily break the chain.
In R v Blaue, the defendant stabbed a young woman. She was told she needed a blood transfusion to save her life but refused it on religious grounds as a Jehovah’s Witness. She died. The defendant argued that her refusal of treatment broke the chain of causation. The Court of Appeal held that it did not. You must take your victim as you find them. If the victim’s beliefs or characteristics make the consequences of the injury more severe, that does not break the chain. The defendant must take the victim as they are.
The principle from R v Blaue is sometimes called the "thin skull rule" or the "eggshell skull rule". It means that the defendant cannot complain that the victim was unusually vulnerable. If the defendant causes an injury that would be minor to a healthy person but is GBH to someone with a medical condition, the defendant is still liable for the GBH. You take your victim as you find them.
When advising a client charged with Section 18, consider whether the evidence supports the specific intent element. If the prosecution cannot prove that your client intended to cause GBH (as opposed to merely foreseeing some harm), you should argue for the charge to be reduced to Section 20. A guilty plea to Section 20 at an early stage can result in a significantly lower sentence than a contested Section 18 trial that ends in conviction. The difference between a five-year maximum and a life sentence maximum is enormous.
Section 20 is triable either way, so the magistrates will decide whether to keep the case or send it to the Crown Court. The defendant can also elect trial by jury. If the facts are serious and a custodial sentence is likely, the magistrates will usually decline jurisdiction and send the case to the Crown Court. Section 18 is indictable only, so it will always be dealt with in the Crown Court regardless of the seriousness of the individual facts.
Both Section 20 and Section 18 can be defeated by a valid claim of self-defence. If the defendant used reasonable force to defend themselves or another, they have a complete defence. If the force was excessive, they may still be convicted of a lesser offence. Loss of control under the Coroners and Justice Act 2009 can reduce a murder charge to manslaughter but does not apply directly to Section 18 or Section 20. However, if self-defence fails because the force was excessive, the defendant may argue that they lacked the intent for Section 18 and should be convicted of Section 20 instead.
Because Section 18 is a specific intent offence, voluntary intoxication can be a defence. If the defendant was so drunk that they did not form the intent to cause GBH, they cannot be convicted of Section 18. However, they may still be convicted of Section 20, which is a basic intent offence. Voluntary intoxication is not a defence to basic intent offences (R v Lipman). So a very drunk defendant who causes GBH may avoid Section 18 but still be convicted of Section 20. This is a key distinction in the exam.
Intoxication does not automatically reduce a Section 18 charge to Section 20. The defendant must show that the intoxication prevented them from forming the specific intent required for Section 18. The jury must be satisfied that the defendant was so intoxicated that they did not intend GBH. Mere drunkenness is not enough — the intoxication must have actually prevented the formation of intent.
Under the principles from R v Powell and English, a defendant who participates in a joint enterprise can be liable for Section 18 if they realised that the principal might intentionally cause GBH and intentionally assisted or encouraged the principal. If the defendant only foresaw the possibility of some harm (but not intentional GBH), they are liable for Section 20 as an accomplice. The key question is what the secondary party contemplated about the principal’s actions.