In Undertale, SAVE is the in-universe name given to save files and the ability to overwrite them. There is one SAVE slot in the game (one per user in the console versions), which can be overwritten by interacting with SAVE Points or by autosaving. In the dialogue, "SAVE" is noticeably written in caps, and it can be conjugated.
A SAVE can be loaded via the game's menu. The game automatically loads the most recent SAVE whenever the protagonist's HP reaches 0. Meta knowledge plays a heavy role in this since the protagonist and other characters have memories of events that occurred before resetting their SAVE. For example, Toriel remarks that speaking with the protagonist is like speaking with an old friend, while Papyrus feels that they look familiar.
If the player tries to load the SAVE in an inaccessible room (if the "Dogcheck" was not turned off) or with corrupted data, the game shows the Annoying Dog in the middle of a black screen, rendering the game unplayable until it is fixed with a functional room or a new SAVE.
The Reset function is found in the game's menu. This function erases most information stored in a SAVE, such as the protagonist's LV and EXP; resetting, however, does not erase certain variables such as the name. Similarly to loading a SAVE, some characters in the game act differently after a reset.
A True Reset is a function available after completing the True Pacifist Route. It erases most data from the
undertale.ini file, exceptions including the Mysterious Door opening and border data on console. The post-Genocide state is in a separate file and unaffected by even a True Reset.
If the Genocide Route is completed, the First Human destroys the world. They then offer the player to recreate the world in exchange for their SOUL. Other than manipulation of the files using a file editor, this is the only way to reset the game. However, accepting this offer also activates a permanent flag in the game's files which affects all subsequent True Pacifist and Genocide endings.
The power to reshape the world...
Purely by your own determination.
The ability to play God!
The ability to "SAVE."
In the universe of Undertale, SAVING the game manipulates the timelines. The use of this ability is exclusive to the character with the highest determination. The first character known to acquire this ability is Flowey, because of the determination he was injected with. His ability to SAVE is lost when the protagonist enters the Underground, as the protagonist's determination is greater than his. Flowey is also noticeably the only character who retains full knowledge of the protagonist's actions before and after loading a SAVE, as opposed to other characters who only have vague memories.
At the end of the Neutral Route, Flowey regains his ability to SAVE after absorbing the six human SOULs. His use of the SAVE ability in this state is analogous to save-states, which he uses in the battle to disorient the player. Another noticeable difference is the number of save slots; while the protagonist can only use one SAVE file, Photoshop Flowey uses four (SAVE files 2, 3, 6, and an unspecified one), although it can be inferred that he can use at least six which possibly comes from the six human souls which he absorbs beforehand.
The SAVE files, in-universe, are created by the characters that can SAVE. There are three SAVE files in the game files (located at
%LOCALAPPDATA%\UNDERTALE on Windows,
~/.config/UNDERTALE on Linux and
~/Library/Application Support/com.tobyfox.undertale/ on macOS):
file0: When a SAVE point is used, the actual state of the world is saved to this file. When the player quits and reloads the game, the game loads this file.
file8: This file is created when Flowey absorbs the six human SOULs and persist in the game files even after a True Reset. It is supposed to be Flowey's file.
file9: This file is used by the game to save the actions of the protagonist automatically at hidden autosaves. It is reloaded after the protagonist receives a Game Over. The game copies
file0and pastes it in
file9whenever the game is reloaded. It is unclear whether this is the protagonist's file, or whether the protagonist's file is
file0and this simply represents the "real" state of the world.
It is optional to SAVE, and it is possible to reach all endings of the game without SAVING. Towards the end of the Neutral or Pacifist Routes, the game acknowledges that the protagonist has not SAVED at all.
Before the battle with Photoshop Flowey, Flowey mocks the protagonist for having made no SAVE files. He makes use of his ability to SAVE and load as usual.
After completing the game in the Neutral Route, the game restarts, and without any SAVE file, the player is prompted to begin a game in the menu.
True Pacifist Route
If the game has been completed at least once in the Neutral Route, then Alphys's side quests are made available, making it possible to play through the game on the True Pacifist Route. All of this can be done without manually SAVING the game.
During the final battle, the protagonist considers SAVING over Asriel's file to defeat him, but it is stated that since they never SAVED before, they lack the power to do so. The story continues as usual, but the game secretly SAVEs itself, preventing the timeline from being lost after the game is closed.
- our reports showed a massive anomaly in the timespace continuum. timelines jumping left and right, stopping and starting... - Sans
- And when I tried to load my save file... It didn't work. Your DETERMINATION! Somehow, it's even greater than mine! - Flowey to the First Human, during his monologue at New Home
- Lines 18567 through 18574 in the strings.txt game file. Retrieved 20 September 2015 from https://pcy.ulyssis.be/undertale/
- Golly, if only you had a SAVE FILE you could run away to... But you were just too STUPID to make one! - Flowey
- it's been a while. shouldn't you SAVE? - Sans
- SAVING over ASRIEL's file seems like the only way to defeat him... But, having never SAVED before, you lack the power to do it. - Narrator