Fallout: New Vegas Combat

Fallout: New Vegas has a combat system that is very similar to its' predecessor, Fallout 3.

V.A.T.S.
The Vault-Tec Assisted Targeting System returns to Fallout: New Vegas allowing the player to freeze combat and specifically target six different limbs at the cost of action points.

Aim down sights
A new feature in Fallout: New Vegas allows the player to aim down the sights of their firearm, as opposed to in Fallout 3 where the "aim down sights" was simply a zoom in feature to the side of the weapon.

Combat damage
Damage calculations that follow are not to be taken as 100% accurate. There are various exceptions in how certain modifiers get included (most notably DT), so this is intended to be a general guide.

First, Dam needs to be calculated, where:
 * $$Dam=Dmg \times Skill \times Cond \times MeleeVats + Bonus$$


 * Dmg = Unmodified, base weapon damage, as seen on individual weapon pages.
 * Skill = A modifier ranging from .5 to 1, as seen for the Fallout: New Vegas skill formula.
 * Cond = A modifier ranging from .5 to 1, based on weapon condition.
 * MeleeVats = If the player is using a melee or unarmed attack, this is set to 2, otherwise, this is set to 1.
 * Bonus = The player's strength bonus (if using melee), unarmed bonus (if using unarmed), or 0.

Second, any critical damage (if a critical roll succeeded) and armor is added in, where:
 * $$Dam_{adjusted}=(Dam \times DR) + isCrit \times (Critdmg \times BC) - DT$$


 * DR = A number ranging from 1 to .15, representing the Damage resistance of the target.
 * isCrit = 0 or 1, 0 if is not a critical hit, 1 if it is.
 * Critdmg = Unmodified critical bonus damage, as seen on individual weapon pages (may be 0).
 * BC = 1.5 if having Better Criticals, 1 otherwise.
 * DT = The Damage threshold of the target. Note that this number cannot reduce Dam (net any critical or resistance modifiers) to less than 20% of its value, see the DT page for details.

Finally, any other multiplicative modifiers are included, such as:
 * $$Final\ damage=Dam_{adjusted} \times SA \times HS \times AM \times DM \times Perks ...$$


 * SA = Sneak Attack modifier adds +100% total damage
 * HS = Headshot modifier adds +100% total damage
 * AM = Ammo type multiplier (such as from hollow-point variations).
 * DM = Difficulty multiplier. 1 on normal difficulty, 0.5 on very hard.
 * Perks = Other damage multipliers from perks such as Lord of Death, Bloody Mess and Living Anatomy
 * ... = Anything else, like Chems or possibly special melee attacks.