Assault is an attempt to or a threat to apply unlawful force on another person in such a way that he believes that such force is about to be applied on him. For assault to be committed there must be present the expectation in the mind of the victim that force is about to be applied to him, and such expectation is intentionally caused in the victim’s mind. It is immaterial that force was not applied on the victim, however if force is applied then it is called battery.
The Criminal Code Act uses the word “assault” for both “assault” and “battery” and it defines assault as:
“A person who strikes, touches, or moves or otherwise applies force of any kind to the person of another, either directly or indirectly, without his consent or with his consent, if the consent is obtained by fraud, or who by any bodily act or gesture attempts or threatens to apply force of any kind to the person of another without his consent, in such circumstances that the person making the attempt or threat has actually or apparently a present ability to effect his purpose, is said to assault that other person and the act is called an assault…”
Assault in the instance of this article will be used as it is used in the Criminal Code Act, to refer to “assault” and “battery”. Assault therefore is the attempt to or the application of force of any kind on another person. Assault can be said to be lawful where a person will not be criminally liable for any force used on another.
Generally speaking assault is unlawful and can amount to a criminal offence; however the law provides for certain exceptions, which are instances where assault can be lawful. Some of these instances include:
- Preventing the breach of peace: Where someone notices another person is about to cause a breach of peace or continue causing a breach of peace in a vicinit, the former is allowed to use force to prevent such breach. The force used must be proportionate to the danger being prevented. The person is also allowed to detain the other from continuing the breach until the rightful authority is present to arrest.
- Suppression of riots: Any person, a peace officer or anyone authorized by a peace officer can apply such force as they deem necessary to suppress a riot.
- Preventing an offence: It is lawful for any person who believes another is about to commit an offence to use such force as necessary to prevent the other from committing such an offence that the offender may be arrested without a warrant. Force can also be used to prevent a person from committing an act that can constitute an offence.
- Preventing a person of unsound mind from being violent: Force can be used to prevent a person who on reasonable grounds is believed to be of unsound mind from being violent to another person or property.
- Defence from breaking in: Any person who has possession of a house, or anyone acting on his authority can use necessary force to prevent another who they believe intends to break-in from breaking-in to the premise.
- Provocation: A person is allowed to lawfully assault another where he is provoked by the other. However, certain things must be in place; first the act or insult must be one that deprives an ordinary person the power of self control, secondly he acts immediately before there is time for his passion to cool off, and lastly the force used must be proportionate to the provocation. Also a person can use force to prevent an act or insult of another where such act or insult can lead to provocation.
- Self defence : A person can use force in defending himself from the assault of another, where he has done nothing to provoke such assault. Force used must not be one that can cause grievous harm or death, however where the assault is one that intends to cause grievous harm or death then he is allowed to use force that is likely to cause grievous harm or death. A third party is also allowed to use force in aiding the self defence of the victim.
- Defending moveable property: A person in possession of a moveable property or anyone acting in his authority can use reasonable force to prevent another from taking the property, or in recovering the property. The force must not be one that will cause harm to the trespasser.
- Defending against trespassers: A person in rightful possession of a property or anyone acting in his authority can use reasonable force to prevent another from trespassing into the property. Force can also be used to eject a person who conducts himself in a disorderly manner, provided harm is not done to him. A person in rightful possession of a property can also use necessary force to defend his possession of the property provided he does not cause the trespasser any harm.
- Exercising right of way: Where a person who has a right to enter a land for the purpose of exercising his right of way is prohibited from entering such premise by the person in possession, if he continues and insist on entering such land, the person in rightful possession can use reasonable force to eject him from the land. However, no harm should be done to him in the process.
- Preserving order on board a vessel: The master of a vessel can use force necessary against any person threatening the peace and safety of any person on board the vessel or the safety of the vessel.
Following all the instances where assault can be said to be lawful, it is important to note that excessive force is not allowed. Any person who is authorized to use force will be criminally responsible for any excessive force. The force used must be proportionate to the action that constitutes the use of force, and such force used must not be to cause grievous harm or death.
 Okonkwo and Naish: Criminal Law in Nigeria. Second Edition
 Section 252 Criminal Code Act
 Section 275 Criminal Code Act, Cap C38 LFN 2004
 Sections 276-279 Criminal Code Act, Cap C38 LFN 2004
 Section 281 Criminal Code Act, Cap C38 LFN 2004
 Section 281 Criminal Code Act, Cap C38 LFN 2004
 Section 282 Criminal Code Act, Cap C38 LFN 2004
 Sections 284-285 Criminal Code Act, Cap C38 LFN 2004
 Sections 286-288 Criminal Code Act, Cap C38 LFN 2004
 Sections 289-291 Criminal Code Act, Cap C38 LFN 2004
 Section 292-293 Criminal Code Act, Cap C38 LFN 2004
 Section 294 Criminal Code Act, Cap C38 LFN 2004
 Section 296 Criminal Code Act, Cap C38 LFN 2004
 Section 298 Criminal Code Act, Cap C38 LFN 2004