Music Editing
Changing music in NT is actually super easy. Each music file in the game is stored directly within Nuclear Throne's folders, so any track can be swapped out with a new one. The only requirements is that it must have the .ogg file extension, and it must have the exact same file name. The length and volume of the track does not matter.
On Steam to access the game files, right click Nuclear Throne in the library -> select Properties -> Installed Files -> Browse. Music can be stored in two separate places depending on version.
Pre-2023 Beta all the music files are stored in the main folder opened. These are all stored with the .ogg file extension.
On 2023/v100 Betas forwards, all the music files are now stored in a 'mus' folder with just their numbers, though any music files should still be converted to .ogg before removing the extension from the name.
For instance on u99r1, the Desert music will be stored as 'mus1.ogg', while on the 2023 beta it will be stored as simply just '1'.
This guide recommends using audacity as a tool as it can convert audio files into ogg. It is also recommended to use the tool to amplify the dB levels. Sounds in-game will usually drown out custom music if it's not loud enough, this is especially notable for runs that aim for late game. Also keep in mind any music chosen will loop back to the start when played in-game when choosing songs.
Here is a list of all the music as it is named in the files:
| File Name | Plays At | File Name | Plays At |
| musThemeA | Title Screen | musThemeB | Character Select Screen |
| musCredits | End Credit Music | musThemeP | Main Menu Easter Egg |
| mus1 | The Desert | mus1b | Desert B-Theme |
| mus2 | The Sewers | ||
| mus3 | The Scrapyards | mus3b | Scrapyards B-Theme |
| mus4 | Crystal Caves | ||
| mus5 | The Frozen City | mus5b | Frozen City B-Theme |
| mus6 | The Labs | ||
| mus7 | The Palace | mus7b | Palace B-Theme |
| mus100 | Crown Vault | mus100b | Vault Guardians |
| mus101 | Oasis | ||
| mus102 | Pizza Sewers | ||
| mus103 | YV's Mansion | ||
| mus104 | Cursed Crystal Caves | ||
| mus105 | Jungle | ||
| mus106 | IDPD HQ | mus106b | IDPD HQ as Rogue |
| musBoss1 | Big Bandit | musBossDead | Boss Defeat Music |
| musBoss2 | Big Dog | ||
| musBoss3 | Lil Hunter | ||
| musBoss4A | The Throne | musBoss4B | Throne II |
| musBoss5 | Mom | ||
| musBoss6 | Hyper Crystal | musBoss6b | Cursed Hyper Crystal |
| musBoss7 | Technomancer | ||
| musBoss8 | Captain |
Ambience themes share the same number ordering as mus for areas, just with 'amb' at the start of it.
Characters victory speeches upon sitting on the Throne is stored here, as well as the noises they make for each of their ultras. While ultras are given names, victory speeches are ordered by mutant ID. These are as follows:
| Mutant 1 | Fish | Mutant 2 | Crystal |
| Mutant 3 | Eyes | Mutant 4 | Melting |
| Mutant 5 | Plant | Mutant 6 | Y.V. |
| Mutant 7 | Steroids | Mutant 8 | Robot |
| Mutant 9 | Robot | Mutant 10 | Chicken |
| Mutant 11 | Horror | Mutant 12 | Rogue |
| Mutant 13 | Big Dog | Mutant 14 | Skeleton |
| Mutant 15 | Frog | Mutant 16 | Cuz (Unused) |
Sound Editing
Editing sounds is much more technical. (WIP)
For the 2021 openbeta, the best tool for sound editing is the Undertale Mod Tool (UMT). While built around Undertale it works for many GameMaker games.
Upon installation hitting 'Open' then navigating to the Nuclear Throne folder, will show the data.win file. Opening this will open all the assets including music, sprites, and most importantly sounds.
The search bar can be used to search for specific sounds. Once a sound is selected, select the three dots by 'Audio file'. This will open that sound which will allow it to be imported or exported and previewed.
Bring in a replacement sound that uses the .wav extension. Similar to above, audacity is a great tool for boosting sound levels and to convert to the right sound file.
Upon finishing select 'File' and 'Save', then replace the current data.win. Changes will be present upon the next time the game is booted.