This perk increases AP regeneration by 25% and attack speed by 20%. It also resets Karma to 0 and grants immunity to critical hits. It can only be taken by a character whose Karma is Evil or Very Evil.
The increased attack speed affects all weapons, not only melee like most other perks that increase attack speed.
When this perk is obtained, a message will appear saying that Karma has been gained.
This perk requires that all 4 Fallout: New Vegas story add-ons be installed, as each add-on increases the level cap by 5.
Lonesome Road (add-on) With the consumption of Rushing water; Having (2nd rank) Melee Hacker and the Slayer perks, the overall increased speed with unarmed and melee weapons will be 110% faster. This being said, the effect on two-handed melee weapons will be up to par on swinging as fast as a one-handed melee weapon; However, One-handed weapons will be uncontrollably fast, letting the player slice, whack or punch as fast as the player can pull the trigger on 360/Left click on PC.
The name of this perk may be a reference to the Clint Eastwood film Unforgiven, in which the character William Munny declares he "ain't like that no more" whenever his past acts of gunslinging and murder are discussed.
xbox360ps3pc When viewed in the GECK, this perk has another effect not stated by the perk's description. This effect is an AP cost reduction of 20% for all weapons. However, the effect uses an entry point of "Calculate Weapon Attack AP Cost" which only affects attacks OUTSIDE of VATS. This meant that the player will not receive any decrease in AP Costs when using weapons (except outside of VATS which is entirely pointless since using weapons outside of VATS require no AP costs). [verified]