Inaccessible Rooms

In Undertale ' s game files, the player cannot access some rooms by conventional means. If the player attempts to access these inaccessible rooms, the "Dogcheck" value will return out of range and cause the Annoying Dog to appear in the middle of a black screen while "Sigh of Dog" or "Dance of Dog" plays.

The rooms below are listed in numerical order.

Room 123
Room 123, also known as room_water_prebird, is a room between room_water_farm and room_water_shop. Its name suggests that Toby Fox may have planned to place it before the Bird That Carries You Over A Disproportionately Small 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. One NPC remarks that they love to catch bugs in their spare time, and the other one asks the protagonist to do something about their friend, who the NPC says has a creepy smile. If the protagonist speaks to the second NPC again, the NPC asks where their friend went. Exiting the area on the left or right crashes the game.

Room 264
Room 264, otherwise known as room_gaster, is a room in which text appears in the pixelated Wingdings font style. Aside from this text, the room is black. The player hears a distorted sound (mus_smile or an altered Muffet's laugh) as the text progresses. Once this message is over, the screen turns black for a moment before the game closes.

Room 267
Room 267, also known as room_2, displays three Froggit sprites before printing the screen red and loudly playing the enemy defeated sound.

Room 271
Room 271, also known as TESTROOM, is gray and has three text bubbles next to one another. Text within the dialogue boxes sways. "* Testmonster" is displayed vertically beneath the second dialogue box.

In the Undertale Demo, this room replaces the Annoying Dog error room if the SAVE is invalid.

Room 272
Room 272, also known as room_water_redacted, is a dark room that has only an NPC in the middle. As the protagonist approaches, the NPC fades and, when spoken to, says "* [redacted]" in Wingdings. This NPC represents one of two theorized sprites for W. D. Gaster. If they leave through the south exit, the protagonist will enter room 270, which is the sound test room; if the protagonist tries to exit this room, Gaster's Theme plays and the game throws an error.

Room 273
Room 273, also known as room_water13, is a room that uses Waterfall sprites. It has 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; they can then use these seeds to reach a pathway on the right side of the room. The exit here leads to room 274, which is a black room with a few red monster placeholder sprites. Walking to the middle of the room initiates an encounter with Flowey, and dialogue from a Neutral Route ending loops while "Your Best Friend" plays loudly. The game crashes if the protagonist attempts to exit the dialogue.

Room 296
Room 296, also known as room_fire4, is an old room that uses Hotland sprites. It has 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," a reoccurring song in Hotland, plays in this room. No rooms connect to this one.

Room 297
Room 297, also known as room_fire10_old, is a room that uses Hotland sprites. Conveyor belts line a pathway that the protagonist must cross to get to the other side. If the protagonist falls off a conveyor belt, they will find themselves in room 298. The exits on the right and left of the room are nonfunctional.

Room 298
Room 298, also known as room_fire10A_old, is a room that uses Hotland sprites. It contains two platforms, one at each end of the room, that conveyor belts link. A single Echo Flower located in the middle of the room says only "* Error!" The left side of the room has a door that leads to room 297, and the other end of the room has a bowl of dog food. The protagonist can find this same bowl in Papyrus's shed.

Room 299
Room 299, also known as room_tundra_placeholder, uses Snowdin sprites and consists of an ice puzzle. If the protagonist attempts the puzzle, the ice pushes the protagonist backward when touched. There is nothing located at the end of the puzzle, and this room does not connect to any other room.

Room 300
Room 300, also known as room_ruins12B_old, uses Ruins sprites and is similar to room 13, the room where the protagonist can find Monster Candy. Instead of Monster Candy, this room has Rock Candy, and the protagonist can only hold one Rock Candy at a time; to take another, the protagonist needs to eat or drop the piece of Rock Candy that they currently have. The protagonist cannot hold two pieces of Rock Candy.

Room 301
Room 301, also known as room_tundra_rollsnow, has a small snowball whose mechanics are similar to the Ball Game in Snowdin Forest. If the protagonist pushes the snowball, it gradually grows until it reaches maximum size. This room does not connect to any other rooms.

Room 302
Room 302, also known as room_water7_older, uses Waterfall sprites, and the player cannot access it unless the file "obj_waterpushrockgen" is edited or deleted. This room has a single Echo Flower that says "* Error!" and several torch-like objects that may be placeholders due to their poor quality. The tops of these objects combust when the protagonist interacts with them. This room may represent an unfinished puzzle similar to the torch puzzles in The Legend of Zelda. Leaving this room crashes the game.

Room 303
Room 303, also known as room_meetundyne_old, is an old version of the room where the protagonist initially meets Undyne. There are some NPCs and a sign that functions as an Echo Flower; it reiterates the last line of dialogue that the protagonist heard from the NPCs. This room also has the scene in which Papyrus talks to Undyne and uses the same dialogue as the final version of the room. After Papyrus talks to Undyne, Monster Kid's dialogue displays even though they are not visible in the room. The right exit leads to room 304.

Room 304
Room 304, also known as room_water_mushroom, has an NPC that asks the protagonist what the "outside" is like. The NPC then asks the protagonist to investigate the room to the right and return to tell him what they found. His dialogue is similar to Ragel's; he talks about being unable to explore because he is rooted to the ground. The bottom exit connects to room 303.