Trouble Modding Games

[Cazzabru98]

Hi i need some help with modding games. i know how to dump romfs and exfs, i also know how to mod the files. But were im stuck is how do i apply those changes to the switch? All the tutorials online only show how to apply the mod in a emulator like riujinx. But no tutorials show me how to apply it to my switch, where do i drop the file in the directory and how to apply it to my game. Am i modding the actually physical game? Or do i need to download the physical game to the sd of my switch with tinfoil first and then mod the game files? Is it even possible to apply mods to the physical game or only to the sd the physical game is downloaded too?

When i dumped my romfs and exfs it went to atmosphere/contents. Do i replace that file with the new modded one or do i keep both old and new in it just rename both? Then how do i apply that new modded file to the game. Is it suppose to happen right away after i drop the file in their coz i did that nothing worked, or is their more steps im missing?

I wanna learn how to do this for my nephew, he enjoys watching randomized pokemon videos so i wanna learn how to do it for him so he can play it instead of only watch it.

I thought it would be similar too 3ds where i can dump the savedata with tinfoil, mod it and then recover the newely replaced modded savedata but pknx doesnt open the save data. Only opens the dumped romfs and exfs files and i dont know how to apply those files when changed

 

[masagrator]

So you know everything, but you are just overthinking stuff. Files go where you unpacked romfs/exefs so atmosphere/contents/*TitleID_of_game*/romfs or exefs. You don't retain any original file, you put there only modified files.
And it just works
No need to activate anything. Just put files to correct place.

 

[Cazzabru98]

So you know everything, but you are just overthinking stuff. Files go where you unpacked romfs/exefs so atmosphere/contents/*TitleID_of_game*/romfs or exefs. You don't retain any original file, you put there only modified files.
And it just works
No need to activate anything. Just put files to correct place.

Oh, when i backed up the files it didnt go under the name of the game. It came in a file with the long number id. So do i rename it to the game i want? Or do i make another folder named the game and drop the long game id file into it?

 

[masagrator]

It came in a file with the long number id

Folder*
That's the "*TitleID_of_game*"

 

[Cazzabru98]

Folder*
That's the "*TitleID_of_game*"

Oh i figured it out, damn i made that more complicated than it needed to be. I do have 1 last question though. Is it the same way for legends arceus?

 

[thesjaakspoiler]

There are save games and the actual game files (code, graphics, sound).
The easiest part is to edit the save games.
Just dump them with JKSV, Checkpoint or GoldLeaf, edit them and put them back.

If no security measures are in place like checksums, encodings or encryptions, then you can try looking for any useful fields to edit. Note that game data is stored in hexadecimal format of you're lucky. Read about big-endian and little-endian byte order and get a hex editor that works for you.
Sometimes it can be really hard to figure out how the savegame data structure works and what the limitations are.

Some games have security applied to their savegames so then you need to understand how that works in order to edit and create a valid savegame again. That is really tricky.
For that people use emulators so they can just stop the game at any given point to see how and where data gets stored.

Most hackers don't touch the game files themselves as for editing those you need to disassemble the code and reassemble it properly. That is hardcore ninja hacking stuff.

For more popular games, there are some threads here and other forums where people build save game editors.
I think for Pokemon those also exist already so that is a good starting point to see how it's all done.

Hacking save games is not hard but it can take a huge amount of time to figure out where what data is.
Note take Atmosphere has an app called Haze that turns your Switch into a memory stick so that you don't need to remove your sd card from the switch to a PC and back again all the time.

A long time ago I hacked some save games for some Pet game to increase the amount of money one collected in the game to buy new cats.
That was pretty straightforward as the money was just a number in hexadecimal format that you could edit.

 

[Cazzabru98]

There are save games and the actual game files (code, graphics, sound).
The easiest part is to edit the save games.
Just dump them with JKSV, Checkpoint or GoldLeaf, edit them and put them back.

If no security measures are in place like checksums, encodings or encryptions, then you can try looking for any useful fields to edit. Note that game data is stored in hexadecimal format of you're lucky. Read about big-endian and little-endian byte order and get a hex editor that works for you.
Sometimes it can be really hard to figure out how the savegame data structure works and what the limitations are.

Some games have security applied to their savegames so then you need to understand how that works in order to edit and create a valid savegame again. That is really tricky.
For that people use emulators so they can just stop the game at any given point to see how and where data gets stored.

Most hackers don't touch the game files themselves as for editing those you need to disassemble the code and reassemble it properly. That is hardcore ninja hacking stuff.

For more popular games, there are some threads here and other forums where people build save game editors.
I think for Pokemon those also exist already so that is a good starting point to see how it's all done.

Hacking save games is not hard but it can take a huge amount of time to figure out where what data is.
Note take Atmosphere has an app called Haze that turns your Switch into a memory stick so that you don't need to remove your sd card from the switch to a PC and back again all the time.

A long time ago I hacked some save games for some Pet game to increase the amount of money one collected in the game to buy new cats.
That was pretty straightforward as the money was just a number in hexadecimal format that you could edit.

This is the way id much prefer to do, dump the save data and recover the new replaced save data but what pokemom app lets me open and edit switch save data? It doesnt work in the univeral pokemon randomizer coz i tried that. Pkhex doesnt work either coz its more of a pokemon importer not a randomizer. I dont know of any editors that can open savedata/main file

 

[masagrator]

Is it the same way for legends arceus?

It is the same for every game.