99

99 is a recurring number in the Baldi's Basics series, with possibly hidden deep lore that has yet to be revealed in Baldi's Basics Plus. It is unknown if the number is giving a hint related to a hidden entity and/or the entire game program itself, or is just a minor symbol.

Class doors
All class doors connecting to classrooms and the Principal's office are labelled with 99.

Baldi's wave animation
The wave animation for Baldi at the beginning of the game technically has 50 frames in it, but the last frame has the filename. This is proven by going through the game's files. If this is just a coincidence or not is up to debate, however.

The frame number is doubled in Classic/Birthday Bash, but the image still has as the final frame.

99 seconds
When the player gets detention for the eleventh (fifth in Classic/Birthday Bash) time and onwards, Principal of the Thing will always give 99 seconds for the detention time.

In Baldi's Basics Birthday Bash, a slowed-down "99 seconds" voice is used in the Hang track for the glitched school.

99 on Baldi's Basics Plus early access trailer
In the Baldi's Basics Plus early access trailer, the number "99" is covering the text "Comic Sans MS". This image can be seen for a split second.

When hacking the game to view the code, on the 13th line of code, the "" text with a number 99 can be seen. That same code also appears on.

Food sprite
The vertical size of the food sprite found in the cafeteria is 99 pixels. If looking very closely, a 9 next to another 9 can be seen cropped.

9/9 Notebooks
In floor 3, there are a total of 9 notebooks. Collecting them all results the notebook counter to read "9/9", which becomes number 99 if the slash (/) is removed.

In Birthday Bash, the player can find two more salmon-colored notebooks in the glitched school to total 9 notebooks.

The screen in the ending
In the ending, after Baldi sings, the game will appear to glitch out for a few seconds, stacking random parts of the song on top of each other. Eventually, the screen will appear, although it is distorted and with new text. The text has the number 99 in the error text.

"THIS PROGRAM IS CANCER"
There is a hidden "THIS PROGRAM IS CANCER" chalkboard written with a bunch of number 99 scribbles. In Baldi's Basics Plus, it is the rarest chalkboard to be generated in a classroom. In Classic and Birthday Bash, it is found outside of the classroom with the red notebook. While it can be viewed more clearly with noclip hacks, the chalkboard is still normally but very briefly seen while searching for the last exit. This is also accompanied by the unusually fallen fences from the western outdoor area's right side.

Rare tree
In the camping field trip prior to V0.3, one of the trees in the forest has the number 99 carved on the wood trunk. Since this tree is very rare and it randomly spawns, it is incredibly hard to locate it.

Farm Leaderboard
When viewing the leaderboard for the time it takes to get to the flag pole in the farm field trip prior to V0.3, all empty leaderboard positions are filled with Baldi taking 9999 seconds to reach the flagpole.

New farm teaser
In one of the teasers for the new farm field trip since V0.3.2, the score in the camping field trip is 99. Though the number is cut off by colored squares covering it up.

99:99
Prior to Baldi's Basics Plus V0.2, the time and current grade results after completing each floor are placeholders. The placeholders for how much time it took the player to beat the level is 99 minutes and 99 seconds (99:99). This is possibly another reference to the number 99.

99 jump-scare
A number 99, in the brown box that was cropped to resemble two eyeballs, has a 1 in 99 chance (1.0 1 %) to appear in the game over screen. It turns red, becomes bigger, and plays a distorted noise before crashing the game.

1999
In the configuration pop-up of versions 1.2 to 1.4.3 in Baldi's Basics Classic, the only listed option for the graphics quality of the game is "1999". It may also be a possibility that the story of the game takes place in the year 1999 as the game's fictional release date. This could be why Baldi is allowed to deliver corporal punishment, without getting in trouble, as this was considered acceptable in some schools in the past. With the world of Baldi's Basics being related to old PC games and having older computer game graphics, the number 99 may also symbolize the same year.

Though it may just be a coincidence, interestingly, many people in the world speculated around the year 1999, that the Year 2000 problem (also known as the "millennium bug" or the "Y2K computer bug") would crash numerous computers and cause world chaos, after the year 1999 came to an end. If this connection between the game and the computer virus conspiracy is valid, this would strongly suggest that the game's own world is coming to a glitched, malfunctioning end as if the Y2K computer bug did happen in the alternate reality.

Decompiling
When decompiling Baldi's Basics Classic and activating the You Can Think Pad, it says: "Comic Sans MS" When the plus (+) symbol is removed, it becomes number 99. 9+9 also equals 18 and Baldi's Basics Classic was released in 2018.

Red balloon
There is one rare red balloon that, when observed closely, has 99 on the top side but flipped horizontally. Since the s are strangely referred to as balloons, the red s that were more corrupted and glitched in appearance corresponds to the red balloon.

puzzle
There is a puzzle room where it is required to count the s represented as "balloons", according to the advice poster. The player must locate and count the s in every room and input the correct number with the four buttons: Adding all these numbers and putting the sums together equals 99:
 * Purple - 8
 * Blue - 6
 * Green - 3
 * Orange - 1
 * 8 + 1 = 9
 * 6 + 3 = 9

99 points
In Field Trip demo, the refueled campfire sometimes yields 99 points as soon as the player puts logs in it.

99 chalkboard
In Baldi's Basics Full Game Early Demo, there is a chalkboard with scribbles and an erased area in the shape of the number 99. It is located behind the roto-hall. In the teaser for the Portal Poster on Basically, Games!'s Twitter, the same chalkboard can very briefly be seen in the Principal's office. In that case, the chalkboard was most likely used as a placeholder.

99 ""
In the Kickstarter exclusive demo, is the name of the variable that the game checks to determine if the game is pirated/cracked. If the value is not 99 (which it is not when pirated), the game sends the player to the anti-piracy screen, unless the files were modified and the anti-piracy screen was replaced with another scene.

Stealthy Challenge
In Baldi's Basics - Challenges Demo, if hacking the demo to show the name of Stealthy Challenge EnvironmentController or ripping off the scenes of the Stealthy Challenge to look at its EnvironmentController, it will say "". for an abbreviation of EnvironmentController, as its seed, and  as its  name for the Stealthy Challenge (The  control how the random level generator generates its level). It is possible that this is a coincidence, though.

99 in the "Thank You" image
In the "Thank you!" image in the Baldi's Basics Kickstarter, there is a number 99 under Cloudy Copter. It is barely seen in the original image as the number has a very similar color as the background color. However, by editing the image to have a dark background color, the number 99 can clearly be seen.

99 on the calculator
In the clip about college from the Kickstarter promotion video, there are two numbers seen on calculators with the numbers 81 and 99.

$99 Kickstarter
Paying $99 for the Kickstarter would give the purchaser a big box copy of the game with original artwork. There were only 99 to go around as well.

Toys
Every price has 99 at the end. On the packaging of some Baldi's Basics action figure items including the Baldi Youtooz box, the number 99 can be seen. Only 99 Baldi Youtooz figures can be ordered per cart.

Baldi's Basics 3-Year Anniversary Presentation
The number 99 appears twice in this video. The first appearance is when mystman12 says 99, but it is bleeped when he reveals the mug, and the second being on a red balloon and possibly on his whiteboard when he exits his room near the end. Also in the video, in the part where he is talking about Baldi's Basics Classic Remastered, on the whiteboard, there are three years: 2018, 2021, and 2117. 2018 + 99 equals 2117.

Trivia

 * In a Twitter post, mystman12 stated that he will be 99 years old in the year 2097.
 * In another Twitter post, mystman12 stated that he has a score of 99/10 for being the creator/developer of the Baldi's Basics series.
 * The music track "99" is also used for the Baldi's Basics Plus Kickstarter video, for the scene where mystman12 is trying to back hold laughing after the mention of "lore" possibly being revealed in Baldi's Basics Plus. Then, he bursts out in maniacal laughter but quickly cutting to a brief-limited shaking scene with Joshua Valent, posing as the character of (possibly where the original, unedited photo of  came from) accompanied with a loud industrial noise.
 * When soundtracks are downloaded from SoundCloud, the "99" soundtrack places 99th on the music list from PC libraries.
 * Additionally, the chalkboard in Baldi's Basics Classic that has the number "99" written all over it, is hidden (similar to how the alternate ending of the game starts nearby Baldi's Office, as well as the character in general). The quote on this hidden chalkboard reads "THIS PROGRAM IS CANCER", and as known by 's speech during the alternate ending,  wants the player to "destroy the game". With this, it's possible that  was responsible for the writing on this chalkboard, and possibly, other instances of the number "99" showing up in the game.
 * The name of the sound file for the "99 jump-scare" game over screen in Baldi's Basics Classic is "ohno", the same spelling shows up in the name for Arts and Crafters' charging pose in Classic, Birthday Bash, and Field Trip demo, "". Other files are 1st Prize's "OH - no" quote named as, Beans' "Oh no!" quote named as "" and The Test's body sprites, which are named as "".
 * mystman12's deleted BaldiComic account has September 3, 1999 as the "birth date".
 * 99 is deliberately corrupted in some versions. A prime example would be Birthday Bash, where the ending consists of s with the number 99 on them.
 * Anim8or, the program for modeling 3D characters in the Baldi's Basics series, was released in 1999.
 * In mystman12's tweet on December 17, 2020, he said that the new farm field trip in Baldi's Basics Plus V0.3.2 was about 99% finished. Although, it actually was 99% done.