Developed in antiquity, this weapon is nevertheless quite prevalent in the post-Great War wastelands.
Brass knuckles, or knuckledusters, take the form of four linked metal rings in a shallow convex formation with a bumper attached to the concave face. The rings are slipped over a combatant's fingers with the bumper pressed into the palm of the hand. When a punch is thrown, the brass knuckles take the majority of the impact impulse, transferring much of the punch's kinetic energy to the target by way of the harder, smaller impacting surface of the metal knuckles. This drastically increases the likelihood of serious tissue disruption and bone damage.
Plunkett's Valid Points was the Raider Plunkett's weapon of choice, a lightweight set of spiked knuckles. Plunkett had murdered many using his fists alone, when his raider brethren were hunted down by Regulators. He sought refuge in Arlington House where he awaits someone worthy to hunt him down and take up the knuckles hoping the bounty hunter will seek out a just cause with it.
Plunkett's Valid Points are a unique version of the spiked knuckles. It inflicts 3 more damage per hit than the regular set of spiked knuckles, and have double the chances of a Critical Hit. The spiked knuckles only have the standard chance at criticals.
Perhaps the biggest selling point for this weapon is the fact that it has one of the lowest Action-Point costs per-shot of almost any weapon in Fallout 3. Assuming you have maximum Agility and the Action Boy/Girl perk, you could string together 7 hits in a single V.A.T.S. attack. Add in the benefits of Ledoux's hockey mask and the tribal power armor, and you can pull off 9 hits, with 13 AP to spare. This combined with the Paralyzing Palm perk will result in paralyzing enemies nearly every time you enter V.A.T.S., enabling the player to kill even super mutant behemoths without much effort.