All of your attacks do -30% damage, but your critical chance is increased by 10%. Technically, this is done by adding a +30 DR modifier to all attacks, which is ignored by armor-bypassing criticals. Because criticals have a chance to kill an enemy instantly anyway, this is a very good trait.
All of your attacks do -25% damage, but your critical chance is increased by 10%.
J.E. Sawyer's Fallout RPG
You take a -2 penalty to damage, but gain a +2 bonus to attack rolls for purposes of determining critical hit results.
Your attacks show a lot of finesse. You don't do as much damage, but you cause more critical hits. All of your physical attacks do -20% damage, but your critical chance is +10%. This trait cannot be selected with Heavy Handed.