Murder and manslaughter are both forms of unlawful homicide in legal systems that use those terms, but they differ mainly in the required mental state and circumstances. Murder generally involves an intention to kill or cause very serious harm, or another form of malice defined by the jurisdiction. Manslaughter generally covers unlawful killings with less culpable intent, such as certain reckless, negligent or provoked killings.
The categories and definitions vary substantially among countries.
At a glance
| Point | Murder | Manslaughter |
|---|---|---|
| Mental state | Higher culpability/intent | Lower or reduced culpability |
| Voluntary form | Usually not called voluntary murder | Voluntary manslaughter may involve intentional killing under legally mitigating circumstances in some jurisdictions |
| Involuntary form | N/A as terminology | Can involve reckless or criminally negligent killing |
| Penalty | Generally more severe | Generally less severe, but still a serious felony/offence |
| Definitions | Jurisdiction-specific | Jurisdiction-specific |
Murder
Unlawful homicide meeting the jurisdiction’s required intent/malice element, often intent to kill or cause grievous harm.
Manslaughter
Unlawful homicide that does not meet the full murder mental-state requirements, or where a partial defence reduces murder.
Intent is more complex than planning
A killing can be murder without long-term premeditation if the required intent forms shortly before the act. Conversely, an accidental death is not automatically manslaughter; the prosecution may need to prove the relevant negligence or recklessness.
Partial defences
Some legal systems recognize doctrines such as loss of control, diminished responsibility or provocation that can reduce murder to manslaughter when statutory criteria are satisfied. These rules differ greatly and have been reformed in many jurisdictions.
Terminology may not exist in your country
South African homicide law, for example, uses categories and concepts that do not map perfectly to the common US/UK ‘murder vs manslaughter’ explanation. Always use the law of the jurisdiction where the offence occurred.
Important note
Criminal-law definitions vary by jurisdiction. This is general educational information, not legal advice.
Frequently asked questions
Is every accidental killing manslaughter?
No.
Does murder always require premeditation?
Not in every jurisdiction.
What is involuntary manslaughter?
A category used in some jurisdictions for unlawful killing caused by sufficiently reckless or negligent conduct without intent to kill.
Why can two similar cases have different charges?
Evidence of intent, defences, statutory definitions and prosecutorial rules can differ.
Sources and further reading
KnowDifferences Editorial Team
Independent explanations with definitions, practical examples and references. Read our editorial approach.