In Undertale, there are sets of rooms that the player must move through in order to progress the game. (obvious, right?) However, during development, some rooms were created then scrapped. This could've been due to inconsistencies or that they were just test rooms.

Nevertheless, we are going to go through all of them.

(Also, thanks to the wiki [undertale.fandom.com] for a majority of these.)

This room was supposed to be located in, Waterfall.

It was located between the Farm and the Shop (room_water_farm and room_water_shop, respectively.) The name suggests that it was meant to be right before the small bird that carries Frisk over the gap. The room has a thin stretch of land surrounded by water on two sides. Grass covers the path, and the protagonist can talk to two NPCs hidden within it. Both are located on each end of the tall grass.

Left End Dialogue:

"(Whenever the girl moves her net, this bug scurries straight into it.)"
"Excuse me... Yes, you, with the striped shirt."
"Can you do something about your friend...?"
"Yes, your friend... The one behind you, with the creepy smile."
"Hmmm? Where'd your friend go?"

Right End Dialogue:

"I'm catching bugs. But the underground doesn't have many..."
"I keep catching the same one."
"Achoo! Tried to catch a bug, but I just caught a cold..."

This is also known to be one of the only rooms that is not Dogchecked. We'll get to that a bit later.

Room 264 is interesting, as it almost looks like it's supposed to provide a bit of background behind W.D Gaster. The room displays shaking, white text in Wingdings font, with robotic sounds playing. This is most likely Gaster writing an entry when he used to be the royal scientist. Entry #17, to be exact. The text displayed can be translated, and reads:

ENTRY NUMBER SEVENTEEN
DARK DARKER YET DARKER
THE DARKNESS KEEPS GROWING
THE SHADOWS CUTTING DEEPER
PHOTON READINGS NEGATIVE
THIS NEXT EXPERIMENT SEEMS
VERY
VERY
INTERESTING
...
WHAT DO YOU TWO THINK?

The game crashes after the last line of text finishes. This room is also not Dogchecked.

Probably a test room, room 267 simply displays three Froggit sprites. Then the screen will print red, and the enemy defeat noise plays. After a bit, the game crashes.

A room to test out the mid-battle dialogue, TESTROOM shows three vertical dialogue boxes. A piece of text shows up saying, " * TestMonster and its cohorts draw near!" Within the vertical dialogue boxes, they will show the following phrases:

"La, la. Time to wake up and smell the pain."
"Though.... It's still a little shaky."
"fhuehfuehfuehfuheufhe"

No more dialogue shows up after the last section. Strangely, the bold word would usually be in red.

In the demo for Undertale, this room would replace room 326 if your save file was invalid.

This room has an NPC that the player can talk to in the middle of it. The NPC just says "[redacted]" in Wingdings, making others think this could be a sprite for W.D Gaster. "Premontion" plays in this room, and when leaving through the south exit, takes the player to the Sound Test Room.

This room contains a long, narrow pathway that leads to a large area of land covered in tall grass. The protagonist can find Bridge Seeds in the grass and can use these seeds to reach a pathway on the right side of the room. The exit leads to room 274, and the bottom crashes the game.

Before Onionsan was added, this room served as a connection between "room_water12" and "room_water14."

277 is just a black screen. You cannot move, interact, or do anything.

I put these two rooms in the same section, as 275 just has a door that leads to 274.

Room 274 has 3 red, pillar-like structures that, while can be interacted with, crashes the game. It seems the game tries to load lines of text, but the file is missing. It is possible to trigger Flowey's first battle, though it is extremely glitched. If Flowey has been killed in a previous run, Toriel's first dialogue plays instead.

At the name suggests, this room was to test the projectiles in Undertale's battles.

The room is a variant of the first Froggit encounter with Toriel. If the Froggit is not killed immediately, Toriel appears and scares the Froggit away. The game then returns to the previous room. The edges of the attack area are missing, with the SOUL stuck at the center of the screen. Red, triangular rays appear out of the SOUL, then sweep to the right side of the screen and turn green.

If the save file is edited then launched, the battle would just restart instead of returning to the previous room.

The name above states that this room was used to test and check all the sprites in the game.

Strangely, though, after Undyne the Undying's head loads, the sprite in the center stops cycling, while every other sprite continues. Pressing space in this room sends you to the Joystick Configuration screen.

Using Hotland sprites and Developer Room sprites, 296 contains a path that goes up and then turns right, and steam vents line the path. The protagonist can access these vents by walking through the wall. "Another Medium" plays in this room. Going down can sometimes load the Omega Flowey boss fight, but that and going right crashes the game.

Undertale's prologue could also occasionally be read out in a dialogue box.

Room 297 uses Hotland sprites, and conveyor belts line a pathway that the protagonist must cross to get to the other side. The exits on both sides of the room are not functional, and falling down leads to 298.

Room 298 uses Hotland sprites and contains two platforms, one at each end of the room, that conveyor belts link. An Echo Flower located in the middle of the room says "Error!" The left side of the room has a door that leads back to room 297, and the other end of the room has a bowl of dog food.

Room 299 uses Snowdin sprites and consists of an ice puzzle. The ice pushes the protagonist backward when touched. There is nothing located at the end of the puzzle, and there is no exit.

Similar in appearance to the room where Frisk gets the Monster Candy, it uses Ruins sprites. The Monster Candy is instead Rock Candy, and the player can only hold one at a time.

This room features the same snowball that can be found during the Ball Game in Snowdin, but there is no hole to push it into. Instead, rolling the ball around makes it gradually increase in size.

An early design of the room just before the second Undyne encounter, the game crashes if loaded UNLESS the file "obj_waterpushrockgen" is edited or deleted. This room also features a single Echo Flower. which says, "Sitting behind rushing water... It makes me feel relaxed." There are also several torch-like objects that the top of them explode when the player interacts with them.

The name suggests that this was supposed to be the room of the first Undyne encounter. Two NPCs inhabit this room, along with an Echo Flower that restates the last line of dialogue from the previous NPC that the protagonist chatted with. A cutscene also plays out when Papyrus delivers his daily report to Undyne, which is the same dialogue as the final version of the cutscene. Despite Monster Kid not being in the room, he says his dialogue after the Papyrus' report is finished. The right exit leads to room 304.

Dialogue from NPC #1:
"We're about to visit Snowdin for the first time."
"You just came from there, right?"
"How is it...?"

Dialogue from NPC #2:
"Hey, I haven't seen you around before."
"It's nice to meet new people, isn't it?"

Both NPCs also have dialogue after you encounter Undyne:
"You should go back to Snowdin."
"I... I don't know you."

This room contains an NPC that can be chatted to. His dialogue is similar to Ragel's; he talks about being unable to explore because he is rooted to the ground. The NPC is unfinished as it uses the placeholder sprite of the Ficus Licker. The bottom exit connects to room 303, the right exit connects to room 305.

[When interacting with a crystal]
"It's a crystal. You've never seen one like this before."

[When interacting with the NPC in the room]
"You... You came from outside, didn't you?"
"People like you are so rare..."
"Please! Stranger!"
"Tell me about outside...?"
"Is everyone out there like you? How terrible." [If the protagonist says No]

"Huh? "SURFACE"? What do you mean?" [If the protagonist says Yes]

"I just meant outside this room."
"If you haven't noticed, my mycelium have bound me to the ground."
"Please! Stranger!"
"I'll make this simple."
"I've spent my whole life in the same spot, in the same room."
"But I've long wondered what lies inside the room to the right."
"Long I've fantasized about entering, and changing my scenery."
"No... Changing my LIFE!"
"Please. Go and tell me what's inside."

"Well, what are you waiting for?" [If talked to again]

"Oh! You're back!" [Unobtainable; intended for leaving and returning]
"How's the room?"

"Oh, thats a relief!" [If the protagonist says Different]
"That's all I need to continue my fantasies. Thank you, stranger."
"My mind is running wild! I haven't felt this way in a long time..." [Talk again]

"So it's the same." [If the protagonist says Same]
"The same..."
"Same..."
"..."
"OK."
"Please leave." [Talk again]

305 is black and has a Memoryhead that disappears.

Room 306 is the battle room. While the battle scene is used in-game, this room does not contain a monster.

Room 321 is as the name says. It's an empty void.

Technically speaking, this room isn't inaccessible, but you're never supposed to see it on a normal install of the game.

Remember those Dogchecks I mentioned back in Room 123? This is the room that would show if a room is Dogchecked.

In short, the Dogcheck function has a range of values ( 0–3, 78–80, 239–241, and 266–335) that would allow the player to enter a room if the value is within these sets of numbers. If the player attempted to access any of the inaccessible rooms, the Dogcheck would return a value out of range (4-77, 81-238, 242-265, and 336-indefinite) and cause this screen to appear.

326 is an error room if the save file is ever rendered invalid. It is a black screen with the Annoying Dog in the center. He could be walking or sleeping, though the sprite doesn't mean anything.
mus_sigh_of_dog or mus_dance_of_dog will play in this room, and the player cannot do anything but close the game.

Your first clue of getting this screen is, on the save file screen, you see two dashes on the location portion of the save file and not an actual location, if you knew you saved at the first save point.

327 is a black screen with Mettaton and Alphys, as seen in Mettaton's quiz show. The player cannot do anything.

Now, we start getting to interesting stuff, and rooms that likely were far into development when scrapped.

328 was used to test the scene before the Asriel Dreemurr battle in the True Pacifist Route. It uses all the final dialogue and final battle sprites of each character. Random sprites flash and scroll during the scene, including the sepia images of Asriel that Temmie Chang had created. After Flowey states that he'll "keep you here forever," the game crashes.

room_bringitinguys was used to test the encouragement given by the monsters before the Asriel fight. Although the encountered enemies are here, the main cast is not.

This room was used to utilize the 'God of Hyperdeath' transformation of Asriel. He moves around just as he does in the final version of his fight, indefinitely shaking his head. After a few minutes, he flies around in his rainbow arc pattern like in the actual battle. He will not attack, and trying to make him do so crashes the game.

This room was used to test Asriel's "Angel of Death" animation. The soul can move around freely, but Asriel will still not attack.

This room doesn't have an assigned name, and there are two different results based on the version.

Until v1.05:
Meant to load the name screen, but crashes as an attempt.

After v1.05 and Playstation ports:
Loads into the Dog Shrine room.

That...was a lot to cover. I had to sleep halfway into making this.

Anyways, hope you enjoyed =)

























































































































































































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