konekoling:

• If you end an encounter in a draw, the game will behave as if you lost, but the victory jingle will still play anyways.
  
• You can evolve a Pokemon that requires a stone to evolve without using an item by leveling it up in battle, and then finishing the battle with a Pokemon with a hexadecimal identifier equal to the needed stone.
  
• All items intended to quadruple attack accuracy actually quarter it instead. Whoops.
• Some of the hidden items in the Japanese releases of Red and Green just have flat-out incorrect coordinates for the itemfinder’s reference, and if you pick up one out of this set of six miscoded items, the other five become unobtainable.
• The aforementioned hidden items can, however, somehow be made obtainable again by moving a fossil item out of your inventory.
• You can use the storage system to get yourself a party of only fainted pokemon. This results in the player character blacking out four steps after leaving the PC
  
• If you catch a Pokemon that has used transform, via legitimate moveset, use of metronome, or otherwise, the game will just assume it was a ditto once it’s in your possession.
  
• You can end the encounter with the Ghost Marowak without a Sylph Scope by just throwing a Pokedoll at it.
• Catching an ‘M with a Hexadecimal identifier of 00 will leave behind an invisible but otherwise Completely Normal Ditto with its previous moveset at level 0 or 80 that needs to be caught or defeated before the battle can properly end. These games have been out for twenty years and we still don’t know why this happens.
• You can buy any of the drinks in the Celadon vending machines as long as you have enough to buy a Fresh Water.
  
• Walking around enough with Pikachu off screen in Yellow can just completely destroy the game for some reason.
• If you force a glitch Pokemon with a hexadecimal value of FF into your party, the game will treat it as a hybrid of both Charizard and the cancel button. The game treats this whole scenario about as well as you would expect.
• Attempting to use the Mew Encounter exploit with a Pokemon with a special stat of over 250 results in encountering a glitch trainer who causes the game to just flip the absolute fuck out when trying to calculate how much money to award you afterwards. This causes the relevant memory poiner to shoot off to god knows where, and as a result it just sets a solid two hundred unrelated hexadecimal values in the game to 99 in the process, filling your party with level 153 Bulbasaur that can only use explosion.
  

jinglefruit:

jinglefruit:

Requirements:
A 3DS with Homebrew already set up [x] [x] [guide]
The braindump homebrew app [preferred] [x]
The pack hack [preferred] [x]
Ohana3DS and Ohana3DS rebirth (For texture hacks) [x]
Directx* - required to use Ohana3DS [x]
A hex editor (For script changes and non texture hacks) [x]
A physical copy of the game you want to rom/texture hack
Atleast 1 GB of space on your SD card. More for some games.
Time - This whole process will take atleast 45 minutes to set up for ACNL, but potentially over 2 hours for larger games using N3DS’s microSD manager.

*I believe Windows is required to carry out most of this process, especially as directx is not supported on Mac and Linux systems.

1) Download everything above that you don’t already have. Once you have homebrew set up (and menuhax/ironhax as browserhax will be patched), install braindump, by extracting it’s files to Homebrew’s ‘3ds’ folder on your SD card, so that it appears on your homebrew menu.

2) Turn on your 3DS and load into homebrew via your preferred method.

3) Run braindump on your chosen title, This step can take over 30 minutes, and will look like it has frozen for the first 5-10 minutes. Just leave it and come back to it later. (make sure you have plenty of free space on your SD card, and that your battery is charged. ACNL requires about 800MB.)

4) When this is completed, remove your SD card and put it in your pc. You will have a new file or folder with a 16 digit number created by braindump, (write down the last 8 digits), copy this onto your pc. Then either;
1) If you had a folder created then these files will already be inside the folder. (from the preferred brain dump link)
2) If you have a .cxi file, copy this into the pack hack and open the hacking toolkit, type cxi, and then type the name of the file, and it will extract and decrypt the exefs and romfs of the game. (from the second brain dump link)

5) Copy the romfs file from this folder and put it in the same folder as the pack hack. Open the pack hack and either;
1) Select the RomFS Extractor, a window will pop up, click open, and select the romfs file, then click go. (from the preferred pack hack link) - or -
2) Open the hacking toolkit and follow the instructions to acquire your romfs (usually typing ‘fs romfs’, or ‘rfsb’. (There are different versions.)

After a few minutes it’ll prompt you to save, save it to your pc.

Once completing this step, you never have to do the set up again, if everything works, you can start from step 6 for all future edits.

6) You will now have a folder called romfs, containing about 30-40 folders with various organised data. Make a back up of these files, so you have reliable, easy to find, unchanged models when you need them. In another copy, make whatever changes you want to these files.
[Outline of the folder layout, and a guide for editting ACNL can be found here]
[A complete guide on making custom villagers by Mayorfuu can be found here]

7) Once you’ve finished making your changes, open the pack hack and select the RomFS Builder. Click open and select the entire romfs folder where you made your changes. Press go and let it run. When it prompts you to save, name the file the last 8 characters from the 16 digit name of the folder the files were dumped in, followed by ‘.romfs’. [Eg. For European copies of ACNL it should be 00086400.romfs, and for US copies, 00086300.romfs.]
Your romfs file should be atleast 720Mb in size.

8) If you don’t already have a folder on your SD card root named ‘hans’ make a new one, and put this romfs file into it. This is NOT the hans folder inside the 3ds folder, you need to have 2 hans folders on your SD card, the one on the root containing only your romfs to load, and one in the 3ds folder with the app files to have it appear on the homebrew menu. If you need more room on your SD card, You can remove the files that were obtained with braindump now.

9) Put your SD card back in your 3DS and open into the homebrew menu, select hans and the game you have made a romfs file for. On this screen, set the “Romfs -> SD” to yes. (It’ll display a message asking if you have a file named the last 8 digits of the braindump number, in a hans folder, so check this is correct and amend it if needed).

10) Click ok, and your game should load with all your changes made. Note that this doesn’t make your changes permanent, you have to load through hans everytime you wish to see them. Loading the game normally will not show your textures, as you aren’t changing anything on your actual game copy.

Updated with some clearer instructions which should help anyone who was getting stuck on the last few stages. And included a link to @mayorfuu‘s brilliantly indepth custom villager creating guide (with pictures!).