cristian43 wrote:I do not understand properly tell me more about it, what is combat theory?
The first sentence is just a descriptive term for the perk.
What this perk does is that if you are fighting an enemy hand-to-hand (rather than using a ranged weapon), this perk will give you a small chance to really hurt them a lot by adding your Strength score to the damage. Normal melee damage is based solely on the weapon.
Example:
Your character has a Strength of 25, and is using a melee weapon with a normal damage range of 10-20 pts.
With 4 levels of this perk, your character would have a (3*4)=12% chance of doing (10-20)+25, or 35-45 points of damage.
If you switch to shooting them, this perk will do nothing at all...but there are separate perks that increase your effectiveness in ranged combat as well.