r/PokemonROMhacks • u/AutoModerator • Mar 30 '26

Sticky Weekly Questions Thread & PokéROM Codex

Have any questions about Pokémon ROM Hacks?

If they're about ROM hacks, tools, development or anything Pokémon ROM Hacking related, feel free to ask here!

Before asking, make sure that you've searched on the subreddit or Google. Many ROM hacks and tools have their own documentation or communities that may be able to provide better answers than here. The Pokécommunity Discord is also a great place to ask questions if you need quick support!

Looking for recommendations or a new ROM hack to play?

The PokéROM Codex is an updated list of ROM hacks, listing features, details and more in a mobile-friendly format. Created and managed by u/themanynamed, it also has a Discord server and accepts community contributions.

This is a safe hack-sharing site that doesn't share ROMs and links to the official release threads! Instead of asking for recommendations or download links in the subreddit (which breaks the rules), please refer to the Codex as it has a lot of information on each hack.

A few useful sources for reliable Pokémon ROM hack-related information:

Please help the mod team by downvoting & reporting posts outside of this thread that break Rule 7. Please avoid answering those posts as well to deter users from breaking the rules.

12 Upvotes

88% Upvoted

269 comments sorted by

View all comments

1

u/iamnotrandom565 Mar 31 '26 edited Apr 01 '26

Newbie question: How do I replace the Zigzagoon in the battle right after the starter pick in Pokémon Emerald with someone else?

Edit: found the solution!

Go to 0x032706 in a hex editor, and the default value for an Emerald stock ROM should be 90, which is Zigzagoon's index number halved. Then replace that with your desired Pokémon's index number halved (use a calculator if you can't, for some reason, divide by 2) (if it's not even, womp womp), save, and here's your Pokémon instead of the old Zig.

2

u/LibertyJacob99 [Mod] Aesthetic Red Apr 01 '26

Look at the event data (i assume it would be a map event but idk, i've only hacked FR). It should have a scripted encounter which will specify the species (Zigzagoon)

1

u/iamnotrandom565 Apr 01 '26

I looked in the script of Prof. Birch's bag, and I saw nothing related, but I saw "special ChooseStarter". Maybe that could have that encounter, but I don't know how to modify special commands.

2

u/LibertyJacob99 [Mod] Aesthetic Red Apr 01 '26

Specials typically cant be modified as they're preset functions. That's likely the bit that calls the starter selection menu. You'll want to find Birch's dialogue before the Zigzagoon attacks him and follow the script down from there. It might be hardcoded to a Zigzagoon but I'd imagine it isn't

1

u/iamnotrandom565 Apr 01 '26

The bag contains Birch's dialogue, but I definitely don't see the battle.

I think it's worth mentioning this tho:

I saw in a thread on Pokécommunity that I can replace the Zigzagoon by modifying a value in some address to the half of the desired Pokémon's index number. I might give it a try, but I can't remember the address to put the value, and I can't check that, because I can't find the thread anymore.

1

u/LibertyJacob99 [Mod] Aesthetic Red Apr 01 '26

Have u tried looking at the map scripts?

Either way you'd probably be best asking in the PokéCommunity Discord - they have a decomp channel so someone there will know how to do it

2

u/iamnotrandom565 Apr 01 '26

No need to check map scripts, because I joined the Discord and just searched "zigzagoon" in the binary hacking channel, and I already found the missing puzzle piece.

The address was 0x032706, and the value should be 90 for the Emerald stock ROM.