Vault 22 Guide for Fallout New Vegas

If you're tackling Vault 22 in Fallout: New Vegas, you're in for a genuinely unsettling experience. This isn't your typical vault crawl—it's darker, more claustrophobic, and filled with shambling horrors that used to be people. The whole place is choked with mutated plants, the lighting is terrible, and you'll burn through ammunition faster than you'd expect. But the loot is worth it, and the quests tied to this location offer some real moral weight.

What Happened at Vault 22

Here's what went down: Vault-Tec set up Vault 22 as a dedicated agricultural lab. The goal? Figure out how to grow massive amounts of food in a post-nuclear hellscape. Makes sense, right? They staffed it with plant scientists, geneticists, and agriculture experts—basically anyone who could make crops grow where they shouldn't.

The research team actually made progress. They cultivated a parasitic spore based on Beauveria mordicana fungus (a real fungus that naturally attacks insects). These engineered spores supercharged plant growth in ways that would've made pre-war agriculture look primitive. Crops matured in weeks instead of months. Yields skyrocketed. For a while, everyone thought they'd cracked the code.

Then things went sideways. The spores didn't stay in the plants. They jumped to human hosts, spreading through the ventilation before anyone realized what was happening. Once inside a person, the fungus took over—slowly rewriting their biology until they weren't really human anymore. Just walking incubators for more spores.

The infection moved fast. Terminal logs (you'll find these scattered throughout the vault) show that people tried sealing sections, implementing quarantine zones, even cutting life support to infected areas. None of it worked. The spore carriers attacked survivors, plants erupted through walls and floors, and the whole facility went to hell in maybe a few weeks.

Author: Tyler Vance;

Source: canelomobile.com

Some vault dwellers actually escaped into the Mojave. They made it as far as Zion Canyon, where they attacked the local tribes before the spores finally consumed them completely. The "Burned Man" Joshua Graham mentions this event if you play the Honest Hearts DLC—those "crazy vault people" were from Vault 22.

Fast forward to 2281. The place has been dead and empty for decades. Nature reclaimed it, but not in any pleasant way. It's a vertical tomb now, five levels deep, with the corpses of its former residents still shambling around.

Dr. Hildern from the OSI (Office of Science and Industry) wants the agricultural data from Vault 22. He's obsessed with it. Here's what he tells you:

The data from Vault 22 could revolutionize NCR agriculture. We're talking about feeding the entire Republic, ending food shortages permanently. Yes, there were... complications with the original research, but that's precisely why we need to study it—to avoid those mistakes and harness the benefits

— Dr. Thomas Hildern

Translation: he knows people died horribly, but he figures the potential payoff justifies the risk. That's where you come in.

How to Navigate Vault 22 Floor by Floor

Vault 22 has five distinct floors, all connected by a central elevator and various stairwells. The layout gets confusing fast—collapsed hallways, pitch-black rooms, and identical-looking corridors will turn you around if you're not paying attention. Before you head in, make sure you're carrying at least 500 rounds of ammunition (seriously), 10+ stimpaks, and ideally a weapon with a flashlight mod.

Entrance Level Overview

You'll find the vault entrance in the mountains northeast of Jacobstown. The exterior is covered in thick vegetation—you can't miss it. Walk inside and you'll hit a small lobby area with a working elevator that accesses every level.

This first section is relatively safe. Maybe two or three spore carriers, a few stationary plants. Nothing that'll kill you if you're even moderately prepared. The reception desk has some minor loot (usually pre-war money and office supplies). Read the terminal entries here to start piecing together the timeline.

There's a common area just past reception with several beds. They're not owned, meaning you won't lose Karma for sleeping. Use this as your fallback point if things get hairy deeper in the vault.

Oxygen Recycling and Food Production

The Oxygen Recycling level is where you'll first see how badly the plants have overtaken everything. The air filtration machinery is half-buried in vines and roots. Spore plants dominate this floor—these things don't move, but they'll spit toxic projectiles at you from across rooms. When they die, they explode into poison clouds, so maintain distance. A hunting rifle or energy weapon works better here than shotguns or SMGs.

Check the oxygen recycling control room for a terminal that details the infection's early stages. There's also a chemistry station if you need to cook up some healing powder or antivenom.

Food Production sits one level down. This floor was the heart of the vault's original purpose—massive hydroponic chambers that now look like something from a jungle horror movie. Giant mantises nest in the darker corners and side rooms. These insects are fast, hit hard, and often attack in pairs. They're vulnerable to shotguns at close range, but you need quick reflexes. Don't let them get behind you.

Author: Tyler Vance;

Source: canelomobile.com

The main objective for "There Stands the Grass" is here: you need to download research data from the terminal in the central grow chamber. The terminal itself is easy to spot (it's the only working computer in a room full of dead ones), but you'll want to clear all the enemies first. Trying to download while under attack is technically possible but incredibly annoying.

Living Quarters and Pest Control

The Living Quarters level hits different than the others. You can see how people actually lived here before everything fell apart. Personal terminals, family photos, barricaded doorways—there's real environmental storytelling. Spore carriers wander the hallways where residents once slept and ate.

The overseer's office is on this level. Check the desk for the vault 22 cave door keycard—it's just sitting there, not hidden in a safe or anything. You'll need this to access the lowest level. There's also a wall safe with decent loot (100+ caps, maybe a weapon mod).

Pest Control is the bottom floor, and it connects to extensive cave networks. This is where things get legitimately dangerous. The caves are darker than the vault proper, the layout is deliberately maze-like, and in some sections you'll run into cazadores. If you don't know, cazadores are the flying demon-wasps that can kill you in about three stings. They're faster than you, hit harder than most enemies in the game, and their venom will drain your health bar in seconds.

Keely, the missing scientist from Hildern's quest, is down here in the pest control testing area. She's been surviving for weeks by staying mobile and avoiding the worst threats. To reach her, you'll navigate through the caves—stick to the left-hand wall rule and you'll eventually find the right area.

Key Item Locations in Vault 22

The HEPA filters cause confusion for a lot of players. You need all three to complete Keely's task. Two are definitely on the Oxygen Recycling level—look around the large air filtration units, specifically on shelves and in the adjacent maintenance rooms. The third filter is down on Pest Control itself, in a side laboratory room off the main testing floor. Miss any of them and you'll be backtracking.

The cave door keycard is straightforward but easy to overlook if you rush through Living Quarters. The overseer's office has a sign above the door and the keycard is just lying on the desk. Grab it before descending to Pest Control unless you enjoy retracing your steps through spore carrier territory.

Enemy Types and Combat Strategies

Vault 22 throws several enemy types at you, each requiring different tactics.

Spore Carriers look like feral ghouls at first glance, but they're different—former vault residents whose bodies now serve as mobile incubators for the parasitic fungus. They move slowly, shamble more than run, but they can absorb shocking amounts of damage. Their attacks carry a chance of infection (more on that in the FAQ section).

Go for headshots. Spore carriers have zero self-preservation instinct, so they'll walk straight into your line of fire. Single-shot, high-damage weapons conserve ammunition better than spraying with an automatic. Incendiary ammunition or weapons like the Shishkebab work exceptionally well—all that dried plant matter on their bodies ignites easily. If you're using energy weapons, the laser rifle's focused beam beats the plasma rifle's splash damage for these targets.

Spore Plants root themselves into floors and walls, which makes them predictable but no less dangerous. They fire toxic projectiles that cause damage-over-time poison effects. When you kill one, it explodes into a spore cloud that lingers for several seconds. Walk through that cloud and you're taking damage plus potential infection.

Never engage spore plants in melee. Ever. Pick them off from doorways or hallway corners with rifles. After killing one, count to five before advancing—that's roughly how long the spore cloud takes to dissipate. If you absolutely must rush through a recently-killed plant's location, take a dose of antivenom first to mitigate the poison. RadAway doesn't help here since this is biological toxin, not radiation.

Giant Mantises nest in the vault's darker sections, particularly on Food Production and parts of Pest Control. They're aggressive, fast, and their chitinous shells deflect small-caliber rounds. These insects love ambushes—hiding around corners or in shadows, then rushing you when you enter a room.

Shotguns are your friend here. The Riot Shotgun (if you have one) absolutely shreds mantises in 2-3 shots. The spread pattern compensates for their erratic movement patterns. If you're using VATS, target their antennae—the game treats this as a critical hit zone and you'll drop them much faster. The key is preventing them from surrounding you. Backpedal constantly while firing, and never let more than one get into melee range simultaneously.

Cazadores only appear in the cave sections beyond Pest Control. If you've explored the Mojave much, you already know these flying nightmares. They're mutated tarantula hawk wasps—huge, fast, and equipped with venom that's legitimately one of the deadliest status effects in the game. A single cazador can kill an unprepared character in 10-15 seconds.

Author: Tyler Vance;

Source: canelomobile.com

Avoidance is a valid strategy. The caves have multiple routes, and you can often navigate around cazador nests entirely. If you must fight them, bring your highest DPS weapon and aim for the wings. Crippling their wings drops their mobility significantly, turning them from impossible targets to merely difficult ones. Keep multiple stimpaks hotkeyed and be ready to spam-heal through their venom. Antivenom completely negates the poison effect, making it worth more than its weight in caps for these encounters. Alternative strategy: bring a companion. Rex or Boone can draw aggro while you light them up from a distance.

Vault 22 Quest Solutions and Puzzles

"There Stands the Grass" is the main quest that brings you to Vault 22. Dr. Hildern wants the agricultural research data, and he's willing to pay for it. The quest breaks down into several stages with a significant moral choice at the end.

Travel to Vault 22 and work your way down to Food Production. The research terminal is in the main grow chamber—a large room with defunct hydroponic equipment and lots of hostile plants. Clear the room (or at least the immediate area around the terminal), then interact with it to download the data. The download takes about five seconds and can't be interrupted by damage, though you'll probably want to clear the room anyway to avoid getting mauled while reading the screen.

Dr. Hildern also mentions that a researcher named Keely entered the vault weeks ago and never came back. Finding her is optional for completing the main quest, but you'll miss out on significant content and a unique weapon if you skip this part.

To reach Keely, grab the vault 22 cave door keycard from the overseer's office in Living Quarters. Head down to Pest Control and use the keycard on the door leading into the cave system. The caves are intentionally confusing—if you're getting lost, follow the left wall consistently and you'll eventually reach every area.

Keely is in the pest control testing section, surrounded by scientific equipment. She's been studying the spores for weeks and reached a conclusion: this research is too dangerous to preserve. She asks for your help destroying the vault by igniting gas vents throughout the facility.

This creates the quest's central dilemma:

1. Destroy the data with Keely: Collect three HEPA filters (detailed in the items section above), then help her ignite the gas vents. This destroys the research permanently, preventing anyone from recreating these experiments. Keely gives you the Sonic Emitter - Revelation as thanks. Return to Hildern—you can lie about the data being corrupted, or tell him the truth and watch him lose it.
2. Preserve the data for Hildern: Refuse Keely's request and take the downloaded data back to Dr. Hildern. He pays you (not a huge amount, honestly) and gives you NCR reputation. Keely finds her own way out eventually, but the dangerous research survives for the OSI to study.
3. Middle path: Download the data, help Keely destroy the physical vault, but keep the digital copy. You technically honor Keely's request while maintaining the option to give Hildern the data later. Or keep it for yourself and show it to Elder McNamara for Veronica's quest.

The "puzzle" elements are minimal—mostly navigation and item collection. The real puzzle is ethical. Do you enable potential agricultural breakthroughs for the NCR, knowing the risks? Or do you permanently delete knowledge that killed hundreds of people?

If you're doing Veronica's companion quest "I Could Make You Care," the Vault 22 data counts as proof of advanced technology for Elder McNamara. But you can only use it this way if you haven't given it to Hildern yet. Complete Veronica's quest first, then deliver the data to Hildern afterward.

Author: Tyler Vance;

Source: canelomobile.com

Frequently Asked Questions About Vault 22

Vault 22 delivers one of New Vegas's most atmospheric and genuinely creepy locations. The combination of environmental horror, tragic backstory, and meaningful player choice makes it memorable years after release. The overgrown corridors and shambling spore carriers create tension that most other vaults don't match.

Successfully clearing all five levels requires solid preparation, decent combat skills, and attention to detail. The moral choice at the quest's conclusion—preserve dangerous knowledge or destroy it—represents the kind of decision-making that defines New Vegas. Neither option is clearly "correct," forcing you to weigh competing values and accept the consequences.

Whether you're after unique weapons, completing NCR questlines, or just exploring every corner of the Mojave, Vault 22 delivers. Stock up before you go, save often, and prepare for one of the game's darkest dungeons. The loot and experience make it worthwhile.