Fallout 4 Critical Hits

How they Work, Damage Formula, and Crit Meter Fill by Luck

Critical Hits in Fallout 4 are player-controlled, tactical opportunities that come from using V.A.T.S.. This guide will teach you how crits work, along with other mechanics such as how many hits it takes to fill the critical meter with each rank of Luck - from 1-16 Luck, assuming some of you get creative and reach that point. This may help you to decide when to stop taking extra luck, as there are other means of influencing the stat, while you can also get a base of 11 by waiting until 10 to get the Luck Bobblehead, among other means to go toward 20 which are mentioned below.

How Criticals Work & Using Them

Filling the Meter
While using VATS - melee or ranged - there is a meter at the bottom of the screen. As you fire or swing on an opponent, the meter will fill. Once full, press the jump button just before the next attack and you'll execute a critical hit, which will land no matter what chance was displayed (ranged). So long as it's 1%, you can use the Critical Hit for full damage, even at extreme distances. The rate that crits fill up is independent of the speed or type of the weapon, or whether it's a standard pistol, automatic shotgun, sniper rifle, or super sledge. These more powerful and slower weapons cost more to fire in VATS, but deliver more powerful critical hits assuming the base damage is higher.

How many Hits to Fill the Meter with X Luck

... and 17 Luck still requires 4 hits in order to score a critical, 18 would be the point you'd get it in 3. Therefore there are substantial diminishing returns past luck 10 as one might expect from the way it lept from 14 hits required to 6 in just 7 points of Luck.

How to Use this Information
If you're thinking going past certain ranks is pointless, realize there is a perk called Critical Banker, which will let you continue to fill the meter and stock up to 3 crits - overflow counts, so that means you're able to fill 2 crit meters with rank 15 luck and 7 shots - not 8.

Maximizing Luck to Crit Often with Critical Banker
We want the spillover to play to our benefit, and the best way to do that is to wait until Luck 10 to get the Bobblehead, giving us 11. You can then take Party Boy (a Charisma Perk) to get +3 Luck while under the effects of alcohol, while simultaneously never being addicted to it. So we have 14 there. One magazine named Live and Love from Revere Beach Station will give you +1 when drinking with a Companion (Dogmeat doesn't count as a drinking buddy). So there's 15. (Thanks Henry!) Additionally, you can find legendary armor with mods to give you luck and go beyond this!. With 'Lucky' gear it's theoretically doable to get past 20 Luck, possibly even 23 total.

Using Criticals Well
For average play, you can target 'sure hits' - close or easy targets - at 95%, and fire one less than you need to crit based on the table above, then target the last shot at a weak point such as the head of a human or belly of a deathclaw (requires minimum 1% chance to target). You can then fire your salvo and use the crit on the last shot. You can use this crit on an entirely different target, or switch weapons after you've built the meter to fire at a distant target and eliminate a threat. Remember - a 1% chance is a guaranteed critical if you use the meter. The Penetrator Perk makes this exceptionally easy to accomplish. Enemies' own body parts will not block those you are targeting, nor will the cover that they cower behind.

Sneak Attacks and Critical Hits: Do they Stack?
In my testing, I found sneak attacks and critical hits are not multiplied together. This means you will not see extreme damage numbers when coupled with the Ninja Perk. However, so long as you are hidden, you can use other mechanics to your favor. You may miss with a sneak attack, but make it a critical and you're able to guarantee the sneak attack works, allowing you 2x more damage being added to your critical. Click here to learn more about stealth and sneak attacks.

Another Critical Source - Making Overdrive

There is a drug that requires Rank 1 of the Chemist Perk to create, and I've never actually found it in-game. This is the only way that I know of to score critical hits outside VATS. It requires Nuka Cola, Acid, and Psycho to make Overdrive. It's an unique drug with its own mild addiction that gives you a 25% chance to crit and +25% extra damage for 8 minutes, enough to clear a building. Sick! In my testing of this wonderful 'product', I found that it tells you when you crit, and the crits deal every bit as much damage - it just relies on you aiming at a weak point manually in order to be as effective as a VATS crit.

Crit Damage Formula

Please note all info below is before taking damage resistance into consideration, which in some cases will greatly reduce the damage taken and make it look like you've done far less than stated here. The higher the damage, the more is taken off by DR. Additionally, playing on Survival Difficulty will result in this new damage being cut in half. Additionally, when saying 'base' damage below, it is without Perks. Someone with Gunslinger at Rank 5 would do 12.5x the damage they see in Pip boy with certain mods, while a person with 0 ranks would reach the high numbers stated here - but the person with Gunslinger would be doing more damage as they're multiplying a higher number.

Critical hit damage is typically the base damage (with mods included) plus the weapon's damage you see in the Pip Boy (with perks included). What follows is an equation of (base damage (with mods) + weapon with mods AND Perks) x multiplier. Multipliers are additive - the base is 1x, so you'd only hit double damage without any perks. If you have Commando or Gunslinger at 100% damage bonus, this means you can go from hitting double damage to triple damage with a crit (the modded factor is doubled hence 3x.). Where it gets more complex are the weapon type bobbleheads that add 25% damage. With them, you'll do almost 4x normal damage (3.75).

Maximizing Critical Damage (Warning: Math!)

If you take the weapon mods that say they add to critical hit damage (improved crit damage), you get a 2x multiplier added on top of the base of 1. So you could get 2 x 3.25 without gunslinger and deal 7.75x the weapon's base damage, or 10.25x damage with gunslinger/commando factored into the equation. A high luck build could therefore make a very powerful sniper rifle focused on crits (with Rifleman) and deal insane damage even at great distances with low hit chances. This modification is available on most types of rifles/pistols, including energy weapons.

The Photon Agitator addon for regular and institute laser rifles/pistols gives a 4x modifier, while also increasing the weapon's base damage. This can lead to some crazy crits that deal up to 3 x 5.25 damage for over 15x the weapon's base damage. So it may be even better than a normal sniper rifle for crits, though it would take a lot of AP to fill the meter. Use Righteous Authority - a unique weapon from working with the Brotherhood early on, which is basically a laser pistol with Lucky Weapon mod - and upgrade it later into a supercharged killing machine with 15% faster crit meter fill and another 2x on the damage multiplier - should get you at least 21x damage.

Another idea is the Two Shot Rifle of any kind. You can use this to deliver big criticals, although there's nothing on par with the Photon Agitator. I assume the Better Criticals there will give you 2x multiplier like the laser weapon variety.

Better Criticals & Bloody Mess
Finally, I'll mention these two. Bloody Mess can add to the weapon's perk damage in the formula, while Better Criticals adds 0.5 per rank. Remember, the multiplier is additive. So, with our photon agitator delivering an extra 4x to the base of 1x (5x), better criticals adding 1.5x, (6.5x) and Rifleman doubling our damage with all types of rifles we would see 3x 6.5 or 19.5x damage - 25x damage with a weapon like Righteous Authority - it comes out to 12.75x the damage you see in pip boy. With Bloody Mess it would be 3.15 x 8.5 for 27x damage with Righteous Authority or any weapon with the Lucky Weapon Modifier. However, many players don't care for Bloody Mess, and I'm one of them.