Here's my escape plan. it begins in level 0, goes to 3999, then to the frontrooms. only class 1 and 0 levels are in here so you could fairly likely begin unequipped and leave the backrooms without using a bunch of objects, save for food and almond water. one thing I'd like to note: this guide won't work if you have "lived a bad life in the backrooms" which I can only assume means if you've done a bunch of bad stuff to the backrooms and its inhabitants. Anyways, without further ado, here it is:
STEP 1: Level 0
Once you first enter the backrooms, you will almost certainly begin on level 0, which is convenient, as that's exactly where the guide begins. as soon as you enter, head in one direction. keep going in this direction, stay on the path no matter what, the only exception being needing to flee from an entity. your goal with this step is to find the manila room. this step is the most dangerous and unpredictable one on this list, and is the single level where you have any chance to run into entities if you are following the instructions.
STEP 2: The Manila Room
Once you finish wandering, and you reach the manila room, you can be relieved, as the longest and most dangerous part of this guide, and your journey, is now over. there will be instructions on how to noclip inside this room. before you exit level 0, learn these, but do not attempt it, as you may be sent to another level. this will be important for returning to reality. anyways, the first tep here is to enter the manila room. you'll notice a chair in the center of the room. walk over and sit down in it. count out 15 seconds of sitting still, although any amount from 10 to 30 works, then get up. immediately walk forwards towards the nearest level 0 wall, do not turn. punch this wall 3 times. which fist you use does not matter. the wall will open up, revealing a dark tunnel. enter the tunnel, the wall will seal behind you. then, simply blink to continue your journey.
STEP 3: Level 7191
After you blink, you will be teleported to level 7191, a large forest with 4 gravel and dirt paths. you will be facing one of the 4 paths once you arrive. which one does not matter, search for path 3. here is where the warning from the beginning comes in. if you walk 50 meters, and you have lived a bad life in the backrooms, you will be teleported to a random level, but almost certainly one with an entity infestation. do not attempt this, if you are not trained and well equipped, you will almost certainly die. if you do not fall under that criteria, walk straight down path 3. continue walking straight. once you reach 750 meters from the starting point, you will see a black square with a door in the middle of it. open this door and enter it.
STEP 4: Level 561
Your work here is simple, but if you do it wrong, you will likely be condemned to either death or long painful suffering, so listen carefully. there are 7 doors, almost all of them lead to death. the ways are always slightly different, but that doesn't matter. go through the leftmost door if you feel like remaining alive and escaping the backrooms. just open it, walk through it, and keep walking forwards. once the door is no longer visible, you will go into a freefall. at a certain point you will reach the bottom of whatever you're falling through, and you will wake up at the last level.
STEP 5: Level 3999
Well, you made it. the final level. here, your sanity will not decrease, although food and water will still be a priority, but they can both be found in eating areas. the level is filled with arcade games, and it has games of almost every game, including games that aren't usually found on arcade machines, like minecraft, roblox, and call of duty, to name a few. this is the one level I recommend you stay in for as long as you'd like, as there are no entities, and the infinite arcade is not something you can expect to see a second time. do not play any of the games if you would be considered "evil", as doing so and losing a game will lead you to a dangerous level. take note to avoid the games listed below, as they lead to other levels, many of which don't have a way back.
Saints' row (the zombie mode, with cheats enabled)
Spore
Stellaris
Crossbow
Super mario run
An arcade machine called "evil"
Another called "unnamed arcade machine"
Once you're ready to leave, whether that's only a few hours after arriving, or a few years, complete the checklist that you got once you entered 3999. once you're done, walk through the glass doors, and you will be sent back to the frontrooms. alternatively, or if the list contains things that need to be done on certain levels, you can noclip through the window right next to the glass doors.