How can intoxication affect a murder charge in Anglo-American law?

In Anglo-American law, intoxication is generally not considered a complete defense to a crime. However, it may be relevant if it negates the existence of a specific mental state required for a particular offense.1

Regarding a murder charge, intoxication can affect the outcome if it is determined that the defendant was incapable of forming the "malice aforethought" necessary for a murder conviction. In such instances, the charge may be reduced from murder to manslaughter.1

It is important to note that while the law recognizes diminished responsibility in various contexts, intoxication is typically distinguished from mental incapacity. Unlike some other legal systems, such as those in Germany, American law generally does not treat voluntary intoxication as a mental defect that excuses criminal conduct, and it is often viewed as an aggravating circumstance rather than a mitigating one in many jurisdictions.2