How To Manually Patch Your ROM Using .bps Files

A lot of people have asked me, ‘Isn’t rom hacking illegal?’ Short answer — no. Long answer… if you distribute a pre-patched ROM with your mod installed then you’re also distributing a copyrighted game. This is where things get sketchy. To avoid allegations of distributing a copyrighted game to people who don’t already own that game, modders turn their original work into patches that ROM owners can inject into a copy of their original game.

I’m going to assume that anyone reading this article came here to learn how to patch a romhack they just downloaded so lets jump right in!


First off, Windows users will need to download and extract Flips (Floating IPS). Mac users should download and extract MultiPatch instead. I’ll be using FlipsI for this tutorial but MultiPatch will function basically identically aside from a few wording differences.

Selecting our .bps

Second, launch flips.exe and a small window with four different options should pop up. Select [Apply Patch] and an explorer window should appear asking you to locate the .bps patch file of the mod you downloaded. For this tutorial, The Legend of Zelda: Dawn & Dusk which I already have downloaded. Once you find this file, double click on it and our next browser should greet us.

Finding our clean ROM

Next, we need to browse to our unmodified copy of Ocarina of Time. Two things to be mindful of here:

  1. Make sure the rom you’ve selected is in .z64 format. This is the most common file type for Nintendo 64 roms but a few variations exist that aren’t compatible with Flips or many other rom hacking tools.
  2. Check any documentation written by the modder whose patch your downloading to find out which region or version your rom must be. Most rom hacks require the v1.0 North American build of a game but it’s always a good idea to double check.

The patch for Dawn & Dusk uses v1.2 of Ocarina of Time as its base so I went out of my way to ensure that the rom I selected said, ‘LOZ Ocarina of Time (U) (V1.2).z64′ to fit all the mod’s’ requirements.

Outputting our patched ROM

Finally, we need to find a suitable output location for our patched ROM. I’ve got a folder specifically for Legend of Zelda romhacks as I find keeping mods in my vanilla folder leads to excessive crowding and difficulty navigating to the desired vanilla rom on certain occasions.

Once we’ve picked a destination, name our romhack something unique.


If everything went according to plan, a window should have just popped up telling us that our new file was patched successfully! Congratulations, you’re ready to play! If you’d like, tweet at @SheeshFr and let me know what romhack you’re playing! 😀

If, however, you didn’t get a success screen at the end, I’ve got an FAQ for you below that will hopefully help you resolve any problems.



Q: I downloaded my patch but it says .zip/.rar/.xdelta at the end, not .bps. How comes?

A: If it’s the first two, then you need to extract the contents of this file. Above, I mentioned using WinRAR or PeaZip. Do this then come back if there was a .bps patch file. If there’s a .xdelta file instead, read my other tutorial for that process.

Q: I downloaded a romhack but it’s already in .z64 format. Do I need to patch it?

A: No, you downloaded a pre-patched rom. You should be able to boot it up like normal.

Q: My rom isn’t a .z64 file. If I rename it to .z64, will this process still work?

A: No, a .z64 file is written differently than an .n64 or .v64 file. If you simply rename the extension, you’re going to get an error when patching and it won’t boot properly either.

Q: I did everything right but when I boot up the file in my emulator, I get an error. What gives?

A: There’s a very good chance the romhack requires 8MB of RAM to be toggled in your emulator. Go into your emulator’s settings and try changing the default memory size to 8MB. If your emulator doesn’t have this menu, boot up the game again (despite a crash), navigate to Rom Settings and change Memory Size to 8MB. You might need to reload your emulator after changing property.

Q: Where can I learn about great ROM hacks?

A: I’m so glad you asked! Keep reading Sheesh Forreal, follow me on Twitter @SheeshFr, or just join some gaming Discords. You’ll definitely get a hold of some new games this way!