Rom-hacks and fan games enjoy great popularity across many gaming communities. Pokémon is merely one community that boasts a highly active rom hacking scene of excellent quality. While certain hacks can be downloaded and played immediately, others, though, are in the form of a mod or "patch" file. You'll need to apply such patch to a ("legaly-owned") ROM file from the original game.
First, download and unzip your desired patch —don't know where to get one? ROMHacking.net is a good place to start— to either your PC or smartphone.
On PC, you only require a browser and internet connection to patch.
• Head to https://slap.nyuu.page
• Upload both your original ROM and the patch to the website.
• Press PATCH
That's it. Just wait a moment and the magic is done. You get a fresh patched Rom that'll work on emulators and (often) also in original gaming systems.
Same method aplies for https://www.romhacking.net/patch/
While this patchers support over a dozen formats, you'll likely to encounter one of these: IPS, UPS, BPS, xdelta or PPF.
Here's some tech data you can skip if not interested:
IPS is probably the most widely supported format among emulators, meaning you may not even need to patch your Rom (some emulators detect the patch if next to your Rom and both names match, and directly runs it), but it doesn't perform checksum checks, isn't suitable for games larger than 16 MB, and doesn't encrypt data (if the patch contains copyrighted material, it cannot be submitted to ROMhacking.net). It doesn't handle unchanged data that is shifted during patching: it considers all data as "changes."
UPS validates the ROM's checksum, supports any size, can increase the ROM size, and allows you to revert a patched ROM to its original form with the same patch file. It doesn't handle unchanged data that is shifted during patching: it considers all data as "changes."
BPS was designed to improve upon and replace IPS/UPS and xdelta. It generates smaller patches, validates the ROM checksum, supports any ROM size, and can expand ROM sizes. The same patch can be applied to both headered and headerless SNES ROMs. It was created by the legendary byuu\near
xdelta validates the ROM checksum, supports any ROM size, supports unchanged data being moved, only checks certain addresses during patching, and generates small patch sizes. Particularly good with large Rom files.
PPF was designed with PlayStation disc images in mind. Can carry undo data and a description file.
(In short:)
Go with BPS unless a particular case specifically calls for IPS. UPS and BPS are from the same author, but think he replaced UPS for good reasons. While BPS is good for cartridge ROMs, xdelta is the right choice for very large files. PPF for disc images.
Before commenting on the offline Android solution, here's a few more cool things you could do with this online patchers:
• Recreate a patch by comparing the before and the after. The patcher just bottle the difference.
• Peel a patch from a Rom (Most patches are one-way. They say how to get there, not how to get back. The exceptions are UPS and NINJA2, which are their own reverse, and PPF3, if whoever made it included undo data).
• Convert to a different format.
• Show the patch info (tells you whatever the patch says about itself).
If by any reason you're unable to reach a computer, there's no big issue. You only need to install an app on your smartphone and have both, the Rom and the patch, downloaded to your device.
I recommend getting UniPatcher from its official github page:
https://github.com/btimofeev/unipatcher
You could also get it from PlayStore (link down below). The process is quite straight forward and not different from the online method. Once you have it installed, you'll be able to patch Roms offline anytime you want or need to.
Of course, there's quite a few offline tools that will accomplish exactly the same on Windows/Linux/Mac.
If you're interested, check
https://www.romhacking.net/utilities/
for an amazing collection of software related to Rom hacking.
Hope you found this handy; let me know in the comments if you're facing any issues or which are your favorite patches.
