Slayer

 is a perk available in Fallout, Fallout 2, Fallout: New Vegas, Fallout Tactics, J.E. Sawyer's Fallout Role-Playing Game, Lionheart, and a Fallout: Brotherhood of Steel skill (skills in this game work like perks do in other Fallout games).

Fallout 1, Fallout 2, and Fallout Tactics
The Slayer walks the earth! With a successful Luck roll, all of your hits in hand-to-hand combat are upgraded to critical hits - causing destruction and mayhem.
 * Note: Despite the in-game description, Slayer does not actually require a luck roll. All hand to hand attacks are upgraded to critical hits.

Fallout: New Vegas
The perk increases the speed of all melee and unarmed attacks by 30%. Note that completely barehanded (no weapon at all equipped) swings will still be at a normal swing speed and unaffected by this perk. This may or may not be patched in the future. This perk does NOT affect Action Point Costs. However the increased speed does cause VATS attacks to execute faster thus reducing the amount of time that the player will be "locked" in VATS sequences where they are left vulnerable. Note: The pre-patch version of this perk on the 360 fails to mention the Strength 7 requirement.

Fallout: Brotherhood of Steel
Each level of this skill increases your Critical Chance for +5% (up to a maximum +25) when attacking a target.

Points requirements

 * 1 Rank : 2 Points
 * 2 Rank : 4 Points
 * 3 Rank : 8 Points
 * 4 Rank : 16 Points
 * 5 Rank : 32 Points

J.E. Sawyer's Fallout Role-Playing Game
The slayer walks the Wasteland! When using unarmed attacks, your successful attack rolls are increased by 30 for purposes of determining critical hit results.

Behind the scenes

 * The image for Slayer except Fallout: Brotherhood of Steel is a likely reference to Conan the Barbarian.