How to Apply Patch to Roms

ROM patching is a common method used to modify Pokémon games, typically for fan-made projects, translations, or gameplay improvements. This process will explain applying a patch file (e.g., .ips, .ups, .bps) to a clean ROM using specialized software.

Legal Disclaimer (Read before you begin)

ROM patching is intended for educational and non-commercial purposes. Ensure you own a legal copy of the original game before downloading or modifying ROM files. Distribution of copyrighted ROMs is illegal and not endorsed.

Required Files:

  1. Clean ROM File: An unmodified ROM of the original Pokémon game (e.g., Pokémon FireRed Version 1.0). The ROM must match the version specified by the patch creator.
  2. Patch File: A file containing the modifications. Common formats include International Patching System (.ips),  Universal Patching System (.ups), and Beat Patching System (.bps)

Patching Software: I use the online patcher, but feel free to install patching software depending on your operating system.   

Patching Procedure:

  1. Select the Rom. Most of the Pokemon rom-hacks are based on Emerald or Fire Red.
  2. Select the patch that you've downloaded. You can find these patches online usually from the developer's Github.
  3. Click Apply Patch. This will download the patched rom to your computer.

Verification and Testing:

After patching, verify the integrity and functionality of the modified ROM:

  • Open the patched ROM using a compatible emulator (mGBA, VBA, RetroArch)
  • Confirm that the game loads correctly and that the intended modifications are present.
  • If the ROM fails to load or crashes, recheck the patch compatibility and ensure the ROM is the correct version.

Best Practices and Troubleshooting:

  • Always use a clean ROM: Even minor alterations can cause patching failures.
  • Verify ROM version: Some patches are specific to versions (e.g., FireRed v1.0 vs v1.1).
  • Maintain backups: Keep original ROMs and patch files in a separate folder.
  • Check patch documentation: Many patch creators provide instructions or compatibility notes.
  • Use checksums (optional): Tools like ROM Hasher can verify ROM integrity via MD5 or SHA-1 hashes.