Self Defence

Self Defence is a complete defence in Criminal law. It is common in Assault and Murder charges. It is sometimes called "Private Defence".

Despite the name, this defence may also be used in the defence of others (Her Majesty's advocate v Carson, Her Majesty's Advocate v Dewar)

Requirements
The requirements for a successful self defence claim were set out in Her Majesty's Advocate v Doherty.
 * The danger must be imminent, and to life or limb
 * There must be no reasonable opportunity to escape
 * The Force used must be proportionate

Imminent Danger to Life and Limb
As Imminent suggests the attack must be in progress, or about to happen. It is reasonable to make a mistake (Her Majesty's Advocate v Owens, Her Majesty's Advocate v Liefer) about whether or not an attack is imminent.

Reasonable Opportunity to Escape
Historically, as seen in Her Majesty's Advocate v Doherty, this was viewed rather harshly, but has loosened up in modern times.

The Escape opportunity declined must have been one that could have been taken without risk (Her Majesty's Advocate v McBrearrty), and must have been the last resort if defending another Her Majesty's Advocate v Dewar

There is no equivalent to "Stand your ground" laws.

Proportionate Force
As made clear in Moore v MacDougall Excessive force is not permitted.

Lethal force can only be use against threats of death or great bodily harm, or to defend a woman facing a rape. It is never possible to use lethal force in the defence of property.