Thank you for this engine, it works really nicely! I only have one question about the wild double battles. On default configuration, all wild battles seem to be double battles. How would I go on about creating specific patches for double battles (like in BW) while retaining single battles in other areas?
Well, you'd need to code that. :P Preferably set up some table with ids for metatiles(like dark grass) that allow double battles and if the tile the player is currently walking on matches, the battle will be double.
Check out src/wild_encounters.c, line 597.