Apart from very rare instances; Level 0 is very repetitive. Where it's nothing but the stink of old moist carpet, the madness of mono-yellow, the endless background noise of fluorescent lights at maximum hum-buzz and approximately six hundred million square miles of randomly segmented empty rooms to be trapped in.
Although Level 0 is mostly made up of randomly segmented rooms, hallways and a few flights of stairs; some cracks on the wallpaper can be found occasionally, showing that maybe people tried to escape this level. Some walls have outlets, but most of them are useless. Rarely, cameras can be found on the ceiling. You can also rarely find groups of rooms stained blood-red instead of mono yellow, and random rooms filled with decorations and other miscellaneous objects. There are also some pitch-black rooms, and every now and then you can hear whispers. It is by far the safest level in The Main Nine. Interactions with entities in this region are rare, but can happen. The known entities on Level 0 include Hounds, Dullers, Facelings, and rarely Lighters. No-clipping through a red wall in level 0 will take you to the closest ceiling to that wall. You can practice no-clipping in these areas.
Colonies and Outposts
There are currently 14 known colonies and outposts on Level 0 of the Backrooms.
Fort Blake
Used to be a major base of operations for the Insurgency, but was destroyed after a battle with Camp Blastdoor.
What's left of it is controlled by a looter group known as "The Rascals".
Stevie-Town
Only 12 or so citizens.
Led by a man named Steve, who acts as the colony's Sheriff and Mayor.
Mostly friendly.
Camp Amber
50 citizens.
Close to "The Hub".
Has a small defense force.
Friendly and open to trade and new citizens.
Backroom Explorers
Consists of at least 178 lost people.
Very friendly.
Has a safety protocol when an entity is nearby.
Wilford Colony
A population of 487 lost people.
Mostly friendly, but hostile if necessary.
Has heavily armed security guarding the colony against entities.
Led by John, who acts as the Mayor.
Security is led by Jake, who acts as the colony’s Sheriff.
Has a transportation system traveling to The Hub.
Open to trade survival equipment, ex. night-vision goggles, almond water, first-aid kit, etc.
Has a small hospital, police force, and fire department.
The "Tom's Diner"
Resides Tom, as the name suggests.
Was a chef before no-clipping into the backrooms.
Has food supplies that could last for another 2 years.
Tom is a cheerful and optimistic person.
The Lucid Group
A population of 8 people that no-clipped while dreaming.
Known to no-clip to different levels and out of the Backrooms.
This group is not confirmed to be real, as only one person has mentioned it, furthermore, the person refuses to reveal the location of the supposed group.
Guide Outpost 01
The biggest remote outpost of The Tourism Guide.
A general population of 80~86 (travelers and by-passers not included).
Always moving, and relocate every few weeks.
Allows new people or by-passers to have a rest inside, or trading.
Good defense and weaponry.
Can recruit new members inside.
Have search and rescue teams ready on standby in case of an emergency.
Union
Population of 362 people.
Friendly people reside here, trading is open.
Has a guarding force outside of the walls to defend the settlement.
The settlement owner is Daniel.
The leader of the guards is Luke.
There are people called level guides who help tell you what happens in different levels.
u/Zamelle
A young male
This person has a lot of resources, and is basically a wandering trader in the beginning levels of the Backrooms.
He likes to trade on easier levels such as Level 4 and Level 0
Republic of Level 153
Outpost of the Republic of Level 153
Has around 50 members
Welcomes in survivors
Is stationed near the entrance to Level 153
Is the most populated outpost of the Republic of Level 153
Will trade Almond Water in exchange for food
Has a relatively large amount of weaponry
Cult of the Fluorescent Lights
Worships the fluorescent lights
Has around 15 members
Has no weaponry, it only worships the fluorescent lights
People here are extremely unfriendly, sometimes they take over other colonies and outposts
They are extremely well fortified, have modern firearms and barricades
They are constantly expanding their territories
Rumors say that they kidnap both people and beings and do cruel research on them
Another rumor say that there is an exit from Backrooms within their area and they are using it to move between the outside world and Backrooms
They dont like RB special ops
RB special ops
Population of over 500 people
They all have psi powers and dangerous guns
Mio honda is in this group,and she has a gun. (God damn it
They are friendly to all but the SCP foundation.
Only 1 person (Rznkr) has a hand gun,it shoots real life bullets,but only can hold drum mags or any other big mag.
Lester Crest Heist Team
A population of about 5 people
They have very large stocks of firearms, weapons of mass destruction and various vehicles
Lester Crest is their leader
Together they are responsible for many heists
They are neutral to everyone else, but sometimes they start destroying everything and killing people for no reason
Hero Association
The Hero Association is an organization founded by the multi-millionaire Agoni that manages all of the cities' heroes.
It operates independently of the government
Agoni also established the National Hero Registry - the database that embraces every recognized hero.
The Hero Association uses a hierarchical class system to organize its heroes, with four classes and individually numbered ranks within respective classes (classes C, B, A, and S).
The Hero Association Staff are the people who send reports to the public, whether it's a monster, natural disaster, or any other crisis.
The Hero Association also has an armed branch separate from the heroes. They are seen protecting the Hero Association Staff at the headquarters and guarding the border of the Z-City Ghost Town; thus, they exist primarily in a support role.
They are fairly well-equipped, having access to armed and armored vehicles, as well as body armor, assault rifles, and grenade launcher
It is very simple to leave. Just exit using an entry point or use your own entry point to go back. Although, exiting through an unknown entry point could lead to even worse places than the Backrooms. If you spend at least 4 days in this level, you will end up in Level 1. You can rarely find a fire exit, and end up in Level 1. You can also break through the floor to go to Level 27. If you find a scratched wall, which is extremely rare, it is weaker, and breaking it will transport you to Level 111. Breaking one of the lights results in a small chance a tunnel will appear, transporting you to Level 1.2. If you wander long enough you can get to the Manila Room or Hallway ZZX. You can take the elevator that leads to Level 153.
Entering Level 0
It is really easy to get here. In Level -1 just take a door that goes to level 0. In Level 49, you will be sent here if you don't meet the requirements. You can get on The Dark Metro to get to Level 0. You can also get here from Level 999. You can also get here from Level 27. You can get here from The Hive by heading down a tunnel. You can also hop into a painting that resembles Level 0 from Level 29. In Level 34, you can go up the sewer grate to get here. If you go into the employees only section in Level 40 you can get here. Also, if you fall through the floor of the catwalks in level 90 you will end up back here as well. In Level 99, if you go through one of the doors you can get to here.