pnach, a text file with a custom extension that the emulator loads code patches from. So it has several advantages over the old method, which could take ~10 minutes to build a mod each time, even with optimal hardware. This method is 100% free, and results are pretty much instant every time you change a file, even while the game is running. This method does not require you to modify your ISO at all! Instead, we’ll be using a code patch that makes the game load files over the local network (your computer’s filesystem) rather than the archives in the ISO.

While this method should work on any device or emulator that runs PS2 games (as long as there’s hostFS support and a way to boot from an ELF), this guide will mainly focus on PCSX2. Please note: This video is pretty old, so if you’re using the most recent version of the emulator, it will look very different! Thanks to new patches by TGE, repacking ISOs– and even CVMs– is finally a thing of the past. In our previous guide on modding Persona 3 and 4 (PS2), it was mentioned you’d need to use paid software UltraISO to repack your modified files into a new, bootable ISO.

Update 12/30/23: For Persona 3 FES, please read this more up-to-date guide on getting set up with mods.