Binary editing in HeartGold

[someone else 2024]

There are various edits I want to do in HeartGold, but can't find information which will allow me to figure out how:

1. Change the Pokémon encounter information, so that I can add various absent Pokémon into the game.

2. Add the fairy type - including registering it, adding a few basic moves of this type, handling all type-matching info for it, and giving the moves to a few Pokémon. (I also have to give the type to some Pokémon, but I do know how I would do this once I have a type number.)

Unfortunately, I'm using my Android device, and as far as I can tell there are no specialized tools and I'm stuck using a binary editor. I did find both basic Pokémon information (such as a temporary hack to give items to specific species of Pokémon, increasing the XP points I get from them) and the evolution info (replacing trade evolution with level-up, replacing trade-with-item evolution to level-up while holding the item, technically 2 separate from evolutions for day-time and night-time) using Bulbapedia info which was good for Gen 3.

[AinsleyHaricot]

Hello,

I've managed to do #1 using DSPRE (https://github.com/Mixone-FinallyHere/DS-Pokemon-Rom-Editor/releases/tag/v1.12.3-beta), simply load in your ROM and use the wild pokemon editor (grass icon on toolbar) to edit the encounter tables.

For #2, BluRose made an excellent tool (https://github.com/BluRosie/hgss-filesys-example/tree/fairy-type) with a tutorial on PokeCommunity. This changes the "???" type to Fairy and adds the Gen 6 type interactions. To make pokemon fairy type, you can use DSPRE (under personal data editor, change type to "???"), or manually hex-edit the pokemon files (changing type to "09" which is "???").

I used Nameless Move Editor (https://github.com/VendorPC/NamelessMoveEditor-v1.0.0.) to edit existing moves to the Fairy type (again, change it to "???"). I don't think it's possible to add new moves or edit animations for existing moves, I just cannibalised appropriate pre-existing moves (e.g. Mirror Shot -> Dazzling Gleam). I believe this is what Drayano did in Renegade Platinum. To use NME you need to extract the move data NARC from your ROM using NitroExplorer (a/0/0/1.narc), then re-insert it using NitroExplorer when you're done.

To give the moves to pokemon, DSPRE has a learnsets tool which is very useful. I've tried to edit TMs to give the new moves but I haven't found a way yet.

I don't know if this will work on an android device, but it's so much easier to do on a pc! Hope this helps :)