Hirdmen who are incapacitated during combat are not killed. Instead, they may be revived during the fight, or be left to regain consciousness at the end of the fight. The number of turns that character remains incapacitated for increases the probability of receiving an injury which then must be healed during camping.
The survival of opponents in combat may influence certain story outcomes and character's conscience. Therefore, it is sometimes useful to enable non-lethal attacks, and ensure that opponents are not being killed, and instead incapacitated.
See main article: Combat