[Other] How to add Roaming Pokemon

Hi guys, I'm trying to do a Pokemon Leaf Green Hack with all 386 Pokemon available in Gen III, I'd like to make all three legendaries dogs available to roaming, independently Starter Pokemon, and add others legendaries pokemon to roaming.
How can I to do this? Exist a hack tool for this? Or just in Hex?
Please help me

I have customized the roamers in my own ROM hack of Emerald and I used a resource for this that might help you somewhat even though you are on LeafGreen. There doesn't seem to be much information on this topic out there, and I ended up finding a page that was apparently in Spanish (which I then ran through Google Translate).

dead link removed

Original: dead link removed

However, it seems to not include LeafGreen specifically (instead it's for FireRed/Emerald), meaning that corresponding offsets will have to be found using a hex editor by taking what you find in a FireRed ROM and searching for the same bytes in the LeafGreen one. I know you probably want to stick to using LG, but there isn't much out there for it unfortunately. Well I hope this helps, as it was all I could really find at the time I was working on this.

Edit (2021): The link is now defunct, page seems to not exist anymore and redirects to a crappy (and potentially virus-laden) survey ad.
Here is the last good snapshot I found using the Wayback Machine. Granted, if you don't understand Spanish you may need to translate it somehow (Google Translate probably): https://web.archive.org/web/2016091...com/t-27909/fr-e-finalizada-pokemon-erramntes

Thank you so much ^^
Just a question: Where I can open the game's script to change the roaming script?

SeraphicLucas said:

Thank you so much ^^
Just a question: Where I can open the game's script to change the roaming script?

Click to expand...

I am not certain about when the roaming script is activated in FR/LG, but someone mentioned it a while back and IIRC there is a special or flag activated when you give Celio the Sapphire gem. That bit of code 'releases' the roaming legendary. I cannot seem to recall what it was though. I do however know that there is a table somewhere in the ROM that dictates what routes the legendaries visit, and it can be edited to your liking.

My doubt is: which program do I use to open the script?

You will need a script editor such as Xtreme Script Editor (XSE), which as far as I know is the best one currently out there. You can even link it to Advance Map by picking "Choose Script Editor" somewhere in A-Map's menu, so when you attempt to open an event script in A-Map it will open it in XSE.

Thank you again ^^