Name
Name the fallen human.
Naming prompt
At the beginning of Undertale, the player is given the choice of naming the fallen human. While the narrative flow and naming screen is seemingly the player naming the protagonist, it is to name the first human who fell into the underground.
Normally, the game asks "Is this name correct?" when asking for confirmation of the name. However, some names trigger a unique response, can have a different impact on gameplay, and certain major character names cannot be used. There is a six-character limit, but this can be bypassed by modifying the game files.
Once confirmed, the name appears as the SAVE file name, and is mentioned in certain situations. The protagonist's name is not revealed until they introduce themselves to the other characters in the True Pacifist Route epilogue.
All names (except "Frisk", as changing that name is required to leave Hard Mode) cannot be changed without performing a True Reset or completing a Genocide Route. On the main menu, the message "A name has already been chosen." appears when "Reset" is selected.
The Japanese naming prompt also allows the player to switch between katakana, hiragana, and the Latin alphabet. If the player first choose a name in English, using Latin characters, and then switch the game language to Japanese, the name will display correctly in the dedicated Japanese font. However, if the name uses katakana or hiragana and the player switches the game language to English, a blurry, narrow font will be used in the dialogue boxes to display the name.
Below are listed names that give a custom response, replacing the default one. Alphabetic characters are case-insensitive and kana are script-insensitive. When played in Japanese, due to being able to enter both kana and alphabetic characters, the same response occurs regardless of whether the English or Japanese name was entered.
Entering a blank name cannot trigger the associated response, as the game prevents the player from selecting "Done".
| English | Japanese | Response |
|---|---|---|
| (Blank name) | — | "You must choose a name." |
| Alphys | アルフィー | "D-don't do that." |
| Asgore | アズゴア | "You cannot." |
| Asriel | アズリエル | "..." |
| Flowey | フラウィ | "I already CHOSE that name." |
| Gaster | ガスター | |
| Sans | サンズ | "nope." |
| Toriel | トリエル | "I think you should think of your own name, my child." |
| Undyne | アンダイン | "Get your OWN name!" |
| English | Japanese | Response |
|---|---|---|
| Frisk | フリスク | "WARNING: This name will make your life hell. Proceed anyway?" |
| Murder Mercy |
ころす みのがす |
"That's a little on-the-nose, isn't it...?" |
| AAAAAA | ああああああ | "Not very creative...?" |
| Aaron | アーロン | "Is this name correct? ;)" |
| Alphy | アルっち | "Uh... OK?" |
| Bpants | バガパン | "You are really scraping the bottom of the barrel." |
| Bratty | アリゲッティ | "Like, OK I guess." |
| Catty | キャッティ | "Bratty! Bratty! That's MY name!" |
| Chara | キャラ | "The true name." |
| Gerson | ガーソン | "Wah ha ha! Why not?" |
| Jerry | ジェリー | "Jerry." |
| Metta Mett Mtt |
メタトン メタ |
"OOOOH!!! ARE YOU PROMOTING MY BRAND?" |
| Napsta Blooky |
ナプスタ ブルっち |
"............ (They're powerless to stop you.)" |
| Papyru | パピルス | "I'LL ALLOW IT!!!!" |
| Shyren | シャイレーン | "...?" |
| Temmie | テミー | "hOI!" |
| Woshua | ウォッシュア | "Clean name." |

The selected name is visible on the main menu, the SAVE file from SAVE Points, most encounters, the overworld menu, and when looking at Stats.
This name is also mentioned by various characters: Flowey, Asriel, Asgore in the Game Over screen, the dream sequences in Toriel's Home and Waterfall, and the fallen human's coffin.
In the True Pacifist Route, the name is mentioned in the VHS tapes in the True Lab. In Genocide Route, the name is mentioned when inspecting the mirrors in Toriel's Home, Asgore's Home, and the Lab console.
In contrast, the name is absent in Flowey's encounters, the New Home story expositions from monsters and Flowey, and the battle with Omega Flowey.

Normally, the name cannot be changed except after a True Reset or after a Genocide Route. However, it is possible to change the name during gameplay by modifying the game data. The following instructions are only applicable to PC versions.
- Open the app data directory for Undertale. On Windows, this should be
%LOCALAPPDATA%\UNDERTALE(typically resolving toC:\Users\USERNAME\AppData\Local\UNDERTALE, where USERNAME is the name of the Windows user). On macOS, this should be~/Library/Application Support/com.tobyfox.undertale/, and on Linux it should be~/.config/UNDERTALE/. - Open the file named
file0in a text editor. - The name is stored on the first line—replace it with a new name.
Numbers and symbols can be added to this new name. If it is longer than six characters, it covers surrounding text, and the text "Easy to change, huh?" appears in the Stats menu. Using a forbidden name has no effect.
The name is also stored in undertale.ini, which is where the name displayed when loading a SAVE file is retrieved from; however, it is overwritten with the name from file0 when the game is saved (if they differ). If the game is reset instead of loading a SAVE, the undertale.ini name overwrites the file0 name instead.
If the name is changed to "Gaster" through the SAVE files, the ability to reset is unavailable as the game restarts upon clicking the Reset button.
| Version tag | Changes |
|---|---|
| May 03, 2013 Demo | The default name is "CHARA" and cannot be chosen. |
| May 23, 2013 Demo | Added a prompt to choose a name. Any name can now be used. |
| June 08, 2013 Demo | Improved the naming prompt navigation: pressing Up while the yellow cursor is at the top of the naming prompt's keyboard now moves the cursor to "Quit" (from "A", "B", and "C"), "Backspace" (from "D" and "E") and "Done" (from "F" and "G"). Pressing Down from these strings now moves the cursor to "A", "D", and "F" respectively. |
| v0.99 |
|
| v1.00 |
|
| v1.05 | Ported all changes introduced up to PlayStation 4/PlayStation Vita v1.05-4. |
| Version tag | Changes |
|---|---|
| v1.001-4 |
|
| v1.02-4 | Fixed the alignment of Japanese names that use Latin characters when they are displayed on the confirmation screen after selecting "Done" in the naming prompt. |
| v1.03-4 | Fixed the issue introduced in v1.001-4 related to the name "Gaster".[1] |
| v1.05-4 |
|
- ↑ "Fixed an issue where the game crashed if you put your name in as a certain character." — PS4/PSVita patch notes from the Undertale FAQ page on the official Undertale website. August 18, 2017. Archived from the original on August 19, 2017. Retrieved July 21, 2026.
- ↑ Undertale: v1.05 Gaster Name Change (PC) on YouTube.