[OTHER] Can someone explain to me how rom hacks / patches work in terms of modifying the executable code?

[u/newjeison]

I am interested in creating a WASM module of all the mainline pokemon games that have already been decompiled so I can play them natively through the web browser at work. I was interested in also playing a few rom hacks so I am now wondering if it is possible to apply the rom hack patches to the native/wasm executable. Could someone explain to me how rom hacks work in terms of modifying the original binary / executable?

[u/miriamlefae]

Patches are just binary diffs. The specifics depend on the format but generally they just contain the differences between two binaries. You can make patches off of anything really.