A character who wants to beat someone up without killing them can choose to do nonlethal damage. This requires the attacker use only his fists or a blunt weapon of some sort. Edged weapons may be used if they have a flat side, but this subtracts −1 from the attacker’s Fighting rolls.
Nonlethal damage causes Wounds as usual, but if a character is rendered Incapacitated he’s knocked out for 1d6 hours instead.
Nonlethal Wounds are otherwise treated exactly as lethal Wounds. This means it’s much easier to render an Extra unconscious than a Wild Card. This is intentional, and should work well for most genres where heroes can take multiple punches before going down for the count, but most “mooks” go out with one or two good punches.