There are five fighting styles and they affect the way you defend, the rate at which you attack, and how accurate you are with your weapon, they are:
To switch fighting styles, type:
You will then see a message similar to:
You were fighting pacifist. You're now fighting berserk.
The fighting styles have two classes. One class is defense assisting, the other is speed assisting. If you are fighting in a defense assisting class, then your weapon will parry more, losing speed and, decreasing eDPS (effective damage per second). If you're fighting in a speed assisting class, your speed will increase, adding eDPS, but decreasing parry,and make you less accurate. The normal fighting style is the most balanced and therefore does not fall into a speed/defense category.
The Defense Class consists of
These fighting styles add to your defense and subtract from your speed. You will parry more often while fighting with these styles.
The Speed Class consists of
These generally add speed and decrease defense. Meaning you will attack faster with less accurate strikes and parry less while being open to taking more hits.
Power attacks can be devastating attacks delivered to your opponent that take a while longer to execute but raise the chance of critical strikes on the person which the attack is aimed.
Fatalities generally occur when your opponent's health is lower than the damage of the attack being inflicted upon them. When you execute a fatality you will receive a message which is similar to this:
Ocelot shouts "HAI!" and in a flash punches his jawbreaker into the scabby chobo's chest, caving it completely in. The scabby chobo spits and froths blood from punctured lungs, staggering around helplessly for an agonizing moment before finally collapsing.
Here is a table showing which classes are able to powerattack and cause fatalities:
Generally when choosing your fighting style you want to keep in mind what type of weapon you are using and who you are facing. When looking to defend against an opponent using Pacifist or Cautious keep in mind the Parry class of both of you and your opponent's weapons. Parry class defines whether an attack can be parried or not. All weapons have a parry class ranging from 0( ) to 2(**). Any weapon can parry attacks from a weapon of equal or lesser parry class. Generally if you are facing a superior parry class you want to fight normal or in one of the Speed Class fighting styles. It should also be noted, that ranged weapons (pistols, rifles, throwing weapons, etc.) cannot power attack normally, so choosing a defense style with a ranged weapon is not as much a loss as a melee weapon.