Help adding an entirely new Trainer to a map in B2/W2

[RubyCarbuncle]

I would like to know how to be able to add a new Trainer to any map in the game. I know that this has probably got a lot to do with Hex editing, but I'm willing to give it a try. Learning how to do this would be a huge step forward for me. So if there is a forum topic that I looked over then I'd love to be able to read it. Thanks.

[Kaphotics]

You have to edit the overworld file of the current map. I have posted a Lua script to be used with DeSmuME which tells you what overworld/text/script entry is being used on the current map.

What you want to do is open the overworld file in a hex editor, and figure out where all the NPCs are. Since there's no editor yet, you have to just duplicate a pre-existing NPC (or just add the proper length of hex) and then place the NPC based on the X/Y/Z coordinates; assign it a script and a sprite and you're good to go.

For actually battling the trainer, it requires a script. On my YouTube channel

shows a custom encounter+battle with Colress. What's neat is that the game's Zone Data decides what background pads to use for the battle. In that video I post the script; the way Drayano and I have added extra NPCs to battle is essentially copying pre-existing scripts and slightly altering their instructions to call a different trainer file.

85 00 2D 03 00 00 00 00

This script instruction tells the game to prompt a battle (0x0085) with trainer # 0x032D, which is Trainer 813 in Kazo's BWTE 2. I was lazy and just edited Colress' previous battle; if one were to copy other files (to make a Trainer 814 exist), then you can also reference that too. That's what Drayano had done for BBVW2. From that pasted script in the description of the video, your script should different as I remove overworld NPCs during the battle.

[RubyCarbuncle]

Thanks for the info, I think I'm starting to get the hang of this. I've been following

that you made for more insight on how to do this. As a test map I've decided to start editing that diner in Castelia. Hopefully, if I can get this working I can make my videos a lot more interesting. Learning this, as well as DS map hacking (I know, so far the tool released only supports Gen IV), might just motivate me to make my own game one day.

Thanks again for the advice, I'll post here again with either more questions or my success on this.