from the manual

There are three types of damage: bashing, lethal and aggravated. Different weapons cause different types of damage to a vampire. Some examples are:

• Bashing – Caused by blunt objects such as baseball bats, tire irons or sledgehammers.
• Lethal – Caused by bladed objects or firearms. For example, knives, swords or guns. Note, Kindred treat bullets as bashing damage.
• Aggravated – Caused by supernatural damage, like sunlight, werewolf claws or mystical attacks.

When a vampire is hit, the vampire has two feats that help absorb or nullify the damage. First, there is the Defense feat that reduces damage from any type of attack. The other feat is called Soak. Soak is the natural resistance that vampires have to various types of damage. When Defense and Soak work together, the Kindred can take little or no damage. The damage that’s absorbed is based on the following:

• Bashing – Armor, Stamina and Fortitude*
• Lethal Damage – Armor and Fortitude*
• Aggravated Damage – Fortitude*

*‑Fortitude is a Discipline available only to certain clans.

Fortitude soaks damage only while it’s active. This means if a baseball bat-wielding thug attacks you, your character could avoid damage from­ a smashing hit if he or she has a high stamina. Conversely, if your character has a low stamina, he or she will take the brunt of any blunt hits that make contact.

from the official v1.2 readme

Every weapon in the game has specific attributes given to it. These attributes are the following:

• Ranged Combat Requirement - This is the minimum ranking at which the PC can use the weapon effectively. The PC can use weapons if his Feat is below the requirement. However, this will mean that he will be causing less damage. Conversely, if the PC's combat Feat is higher than the minimum, then he will cause more damage.

• Damage Potential- Damage Potential is the maximum potential damage your character can do with this weapon at your character's current skill levels. The actual damage might vary if the opponent can defend against bullets (i.e. if they are supernatural, or if they have body armor).

• Lethality -This is how much damage the player can cause with the weapon per die.

• Feat Adjustment - This is the difference between the weapon requirement and the character's combat Feat. This can be either positive or negative.

• Base Damage- This is the minimum amount of damage that the weapon can cause.

Whenever there is a hit, the damage is then calculated in the following manner –

Damage Potential = Base Damage X (Lethality + Feat Adjustment)

So, if the PC, who has a Melee combat Feat of 5, uses a Knife which has a Melee Combat Requirement of 4, Lethality of 7, and Base Damage of 3, then the Damage Potential is

24 = 3 X (7+1)

Now if the player's Melee combat skill is 3, then the Damage Potential is

18 = 3 X (7-1)

It's important to realize that a player is only deadly effective once his combat Feat is above the requirement of the weapon.

Note, the target's defense and soak can absorb the damage and lower the Lethality number. For example, if a ghoul has heavy armor, which has a Defense of 2, there is a chance that 2 Lethality dice can be removed from the player's roll. So, in the first example, if the PC hits a ghoul with the knife and the ghoul makes both Defense rolls, then the Damage Potential is

18 = 3 X (7+1-2)

So, while a player can achieve a high damage potential with any weapon, the damage can be negated if the target has a high defense or Soak Feat.

The type of weapon and the defender plays and important role in what type of soak dice are being used.

To successfully defend or soak an attack, a roll is made behind the scenes. When there is a chance to soak or defend, a roll is made on a d10 (ten sided die). If the number is 7 or above, the defender successfully negates one die.

In summary, combat can be thought of in the following manner. The high lethality weapons are much harder to defend against and the high base damage weapons are the finesse weapons.