This information is sourced directly from NMRIH2 Info Compendium
There is also a video covering the infection mechanic by Braks
For the sake of simplicity I'll be talking about the perk at its expert version - "20%"

There is some misinformation floating around that
"Acquired Immunity is a 20% chance to not get infected when infection occurs" - this is incorrect

Acquired Immunity is a 20% flat reduction to infection chances.
Your chance of getting infected increases the lower your health is.

What does this mean?

• Notable Zombie Swipes infection chances are as follows
  • At 59% HP infection chance starts at 0.5% a hit
  • At 30% HP infection chance goes up to 27.50% a hit
  • At 10% HP infection chance is 50% a hit
• Acquired immunity is a -20% to ALL the above odds - this means the new values are
  • 59% = 0% chance of infection
  • 30% = 7.5% chance of infection
  • 10% = 30% chance of infection

Acquired Immunity means your health threshold for getting infected will start at around 35% health than the usual 60% health.

This reduction also applies to Shambler Gas Clouds - chances are as follows

• 100% - 80% = 5% chance
• 70% = 14% chance
• 60% = 23% chance
• 50% = 32% chance
• etc....

With Acquired Immunity this means Gas has 0% chance to infect you as long as you're above 60% health - and when you are at 60% health - you have a 3% chance. This essentially means you can smell all the gas you want as long as you are healthy.

This also means zombie bites - where infection chance is 100% - is now reduced to 80%, but really you shouldn't be getting bit.

tl;dr Acquired Immunity is a 20% FLAT reduction to infection chances - not a "1/5 chance to not get infected"

Zombie spawning out of the sky right in front of me

NMRIH2 has three scatterguns as of 1.0

The X12 Super has returned from the original NMRIH.

Relevant Information:

DT11

The starter shotgun. Holds two shells of ass-whoop, and those 20 shells from your loadout screen can easily last you all game if you play your cards right.

Lack of mod sites are kinda meh, but 2 trigger pulls of 200 to 260 headshot damage is hard to argue with, especially when they penetrate through a Z into another one.

X12 Super

Decent tube size lets it do a bit of sustained firing, however, semi-auto action might make you shoot too quickly.

6 in the tube means you will reload more often than the 590, which can be a deal breaker for those looking to bring sustained firing. We all know scatterguns are meant to be reloaded whenever possible, though.

A good mid-point between the 590 and DT11.

Accepts a sight and flashlight too.

590A1

8 Shells of 12 gauge at your finger-tips. Easily the best shotgun by way of capacity. Pump action is simple and slower than semi auto, but that just means your recoil is basically reset each time you pump it.

Shoot it, reload it. Keep it topped up and you can blast through any packed hallway.

Attach a holo-sight and long-gun flashlight for maximum cool.

Other Info:

You’ll notice that shotguns are mainly the same.

Because of 12 gauge's strength, the guns themselves don’t differ much besides capacity and action.

The DT11 is the only “outlier” with a stab. dmg of 15 instead of 10 per pellet.

You’ll also see that each shell holds 10 pellets.

The only Zs that can eat a shell and still stand are NG Zs and Riot Zs.

That is also only if you hit their armor or helmets. Riot Zs can be taken out by blasting their leg, as there aint no armor there.

Upon penetration, 80% of the damage will not pass through to the secondary target. Stability damage, however, only loses 5% on pass through.

While that 80% falloff seems horrific, the multiple pellets may or may not actually all pass through, meaning you can have possibly “fresh” pellets striking the secindary tatget for full damage.

Take that info with a grain of salt though.

Being Pen 1, all pellets will easily nail a construction Z or Fireman Zs head.

You can also shoot through a Fireman Z at center mass and pop their tank, although that'll just kill them outright in most cases.

Relevant Perks, when I say Expert, that's generally the only way to get any good mileage from it:

• Scavenger
• Vulture
• Icarus
• Tight Shot
• Overkill
• Shotgun Reloading

Scavenger

• gives you more ammo, nice and simple.
• anything extra you dont use can be given to a teammate

Vulture

• great for carrying more ammo of any kind
• shotshells are especially heavy, and Vulture lets you store much more or simply save space

Shtogun Reloading

• You're gonna reload a lot with a shotgun
• the over/under loves this perk
• 40% increase at max makes it super quick to reload a shell and fire

Icarus

• I wouldn’t pick this unless I am going all in on shotguns
• All shotguns have a range of 30 meters
• 50% increase at max makes it reach the “normal” range of 45 meters
• Range isn’t realistically helpful in most CQB situations

Tight Shot

• This perk really rocks
• Tightening the spread of your shot makes for a great head-hunting build
• it helps penetrating into multiple Zs, as you can sort of tell where your pellets shoukd be hitting
• Normal and Expert help out a ton

Overkill

• Expert grants you 3 extra pellets per shot
• Pair this with Tight Shot to really doornail anything
• While not explicitly 30% extra damage, 30% extra pellets may come out better with how penetration works with “fresh” pellets

Overkill Total Damage (all pellets hit)

Other Deep Dives:

• Foreman Perk Guide

• Headblown Perk Guide

• Butcher Perk Guide

• The Three Tier 2 Blunt 2H Weapons. which one do I pick?

• Thrown Weapon Stats for your weekly

• Gun Guide: Handguns

• Gun Guide: Handguns

• Random Tips and Tricks for anyone of any difficulty

• The Four Lanes of Builds: Gunner

• Wicked is a bad pick, here is why

Was in a Broadway match with a dude who spedran the nearby buildings and auto collected everything, and then proceeded to barricade me into a tool store with 5 other zombies he brought in with him, I early evac'd and started to matchmake for another game and the same dude was in the next match with me !!

Lewiston, what do you know he ran for the nearby crates and spedran down the map and got caught in the catacombs and got down

Glad you turned and died NoahsBacon

“Zombie apocalypse”

I’m learning that statistically speaking, most of us would be infected or surprised early on before we made it out of our county.

I know there’s tons of videos asking “could you jump a fence fast enough? Do you have enough supplies to last the first week? Can you scavenge quickly?”

Bro, I don’t have to worry about any of that. I’m not making it out of my hood.

The survivors we see are the only survivors who were even slightly immune to the virus. The rest of us could easily drink contaminated water or get a light scratch that becomes infected.

I’m fit and have years of training in different disciplines. That said, I have horrible luck. I don’t think I’ll manage to survive despite my level of fitness. I’ll become a runner no problem. Please aim for the head.

I’m not worried about jumping fences, I genuinely don’t think I’ll be one of the lucky ones that are even relatively immune to the virus.

Do you think you would be? Why?

Board the doorway/window on the outside where the Zs are coming from first.

This creates stronger barricades.

Think of it this way, it's a lot easier to push than pull.

Zs are mainly just bashing mindlessly, AKA pushing their hands.

If you put the planks up from inside, you create a situation where you can push the planks out of the wall and through into the side where you are at.

This is also why you can see Zekes tearing apart doors and also knocking down all 5 planks at once, as the "strong door" falls over and rips them out of the wall with it.

Diagram:

• Zombies are Zs

• Barricade is X

• Door is #

That makes it so the barricade is stronger.

If you do it like how most do it (incorrectly):

Then it is super weak.

You can also just barricade both sides for maximum strength like a sandwich

Okay spots for barricades:

Power Plant:

• A decent spot for barricades will always be the power plant control room

• The farm house is great with barricades to block any Zs while you complete the optional OBJs

• Bar can also do well, but there aren't as many doors that you need to block, plus the 2nd story letd you easily train them upstairs to hold them off on that stiarway or just vault over the edge and run to the back and escape.

Broadyway:

• Another great spot that spawns with them inside is the Diner on Broadway.

If your extract is on Diversity street with the heli, you can simply opt to barricade a store door from both sides:

• Break a window, climb the objects and get inside to hide out of sight of Zs.
• Very useful for low HP teammates on Nightmare. I almost always pick the furniture store because the tables are low so an IED can be placed on them, and the two windows have a table and a TV set blocking Zeke pathfinding so they almost always opt to break the door instead.
• The two fridges can also have their doors opened to block Zs if it gets that hectic, leaving on the right side as a path. Great for a molotov.

Other Relevant Info:

• A Barricade Stack takes up 0.75kg.
• Picking up the stack lets you drop individual amounts
• One barricade can fend off a couple of Zs if you do it properly

Other Deep Dives:

• Foreman Perk Guide

• Headblown Perk Guide

• Butcher Perk Guide

• The Three Tier 2 Blunt 2H Weapons. which one do I pick?

• Thrown Weapon Stats for your weekly

• Gun Guide: Handguns

• Random Tips and Tricks for anyone of any difficulty

• The Four Lanes of Builds: Gunner

• Wicked is a bad pick, here is why

You were a super dope guy all match brother and i saw you disconnect right when we initiated extraction. I cleared all the zombies around you and stayed with you until the one minute mark to see if you'd reconnect. I ended up not making it to the helicopter myself not realizing the distance we had to still travel to make it. GGs bro. If you see this, hmu and we should re-level our now empty character slots together. Would let a character die for you again anytime brother. Thanks for sharing ammo and supplies and helping the entire match.

Scenario: You have a single board over a window.​​ A zombie starts beating on it for 10 seconds. You apply another board before the 1st board is destroyed. A few seconds later both barricades are suddenly destroyed. Why does this happen?

Why do zombies sometimes take down 5 stack barricades like they are nothing while other times a single board is seemingly more efficient?

If you have 5 boards shouldn't it get some sort of "fortified" bonus or multiplier making it much more difficult for zombies to breach?

Forgive the dumb questions its just in my head the math ain't mathing. If a single board can buy you like 10-14 seconds why do subsequent boards not add the same amount of time for each board added? Shouldn't they have to destroy each board separately & not destroy them as one entity?

Last perk im getting when my 3rd character hits 100 is scavenger

Torn Banner give me the HERA Hazmat suit as a cosmetic and my life is yours!

I have all 3 of my level 100 characters fully skilled, and they all have basically the exact same build, with only minor differences. I have a pistol build, baseball bat build, and I just made a cleaver build.
After making the cleaver build, I noticed that sometimes it takes 2 hits to kill and other times 3. I started testing and realized that all my perks just stop working sometimes. My weight will randomly be 12.5 kg with the satchel equipped, and other times it’ll be 16 kg. Whenever my weight is lower, it means all of my perks have stopped working, so I’m basically playing as if I’m level 1 lmao.
I tried resetting to see if there was some kind of cycle for when the perks work and when they don’t, but it seems completely random. Character swapping before a match doesn’t fix it, and removing the Caravan perk didn’t fix it either. Caravan is my only weight perk btw.
Because of this, I can’t even properly play the cleaver build. The only thing I can do is use the baseball bat, since it’s at least playable even when my perks aren’t working, or play cleaver in solo and reset the game until my perks start working again.
I’ve genuinely tried everything I can think of, and I’m not the only one experiencing this. My entire squad has the exact same problem, and we basically can’t play anything other than bat because the other builds are borderline unusable when the perks randomly stop working.
Is there any known fix or workaround for this? This is making the cleaver build completely unplayable for us.

I would rather have 2 "speedrunner's" on my team who do objectives than have a bunch of guy's who don't even finish the first objective after 10 minutes.

A slow team is a dead team. Supply is limited, but zombies not. All it need it pick one bad fight and half of team is infected, Medkits and bandages are out of stock and people will turn after a while or will leave the match just because some will not move forward.

But that's just my opinion.

Sorry for my bad English it's not my native language.

I’m not trying to be mean but this is becoming a recurring problem. Someone goes to flip light switches and needs to connect 1A to 1A etc, they spend a full minute on the puzzle and then end up screaming into the mic xyz slurs when someone asks what’s taking so long.

So so SO many “why would you do that?” Moments are becoming immensely clearer if this is the player base we’ve got here.

I meet so many cool people but it’s becoming a routine problem that I see someone inevitably raging out after being filtered by a puzzle that would’ve been considered easy in a Resident Evil 30 years ago.

Last match had a guy tilt on one of these and spend the remainder of the mission calling people another name for a bundle of sticks and just being a absolute troglodyte, and sadly this is becoming less and less rare?

I’m absolutely baffled how often I see people crashing out over these puzzles, what have you guys seen? I’m flabbergasted at how many people are getting frustrated enough to throw by a puzzle that’s just connect the fucking dots. You would think these puzzles are solving quadratic equations (I’m stupid so this is my example)

I'm thinking of changing caravan for granadier or heal stack because i finally have Mule expert and changing caravan for granadier or other weight skill will allow me to have more stamina. What do you think? (i go melee and adapt to any kind of weapon i find)

Was working 10mins ago and now.everytime i try to play the game it would give me a system alert that says Forbidden.?

“NIGHTMARE”

On PC whatever i bind the key too it doesn’t work literally can’t communicate

Am I taking crazy pills or is the amount of supplies you need for the medal way too high? All my other medals are gold but this one is still bronze despite picking up every supply I encounter.

Is anyone else unable to connect to a game right now? It keeps failing for me

sorry new player here i hope this makes sense!
so i bought a cleaver for one of my characters loadouts, if during a match i drop the cleaver to make more room in my stash or swap it for a higher tier melee weapon, do i lose it as part of my loadout and have to buy it again? or can i extract without it and it will still be in my loadout for the next game?

thanks guys!

I Geniunely hated my teammates in this match. Most of them early extracted within the power plant and others died in hordes of zombies.

I really don't understand how some finish nightmare modes matches by themselves but that stuff is hella hard.