- After defeating the first five trainers on Nugget Bridge, fight the Rocket Grunt that gives you a Nugget.
- Make sure you lose to him on purpose.
- Afterwards, you can fight him again; each time he fights you, he will give you a Nugget, so you can can do this repeatedly until you win against him.
However, what a lot of people don't know, and what I just figured out today, is that this glitch doesn't work in Spanish versions of FireRed and LeafGreen. I attempted this myself on a used Spanish LeafGreen cartridge that I recently got, and you can only fight him once, even if you lose against him. Once you lose against him, he won't attempt to battle you again, and due to this, he won't give you another Nugget. Instead, he'll talk as if you defeated him earlier. This is similar to Generation I, where the glitch doesn't occur in any of those games either (as far as I know).
This makes me wonder which versions of the game this works in, and which ones it doesn't. I know it works in the English games (both v1.0 and v1.1). I presume that it works in the Japanese games, since it came out before the English games, but I haven't tested this. I haven't tested the other European versions, either (Italian, German, and French), so I'm curious if the glitch works in those games or not.
It also makes me wonder what other glitches were fixed in later releases. If I find anything else, I'll be sure to mention it here. This isn't the first time I learned of a glitch being fixed in a Spanish release (don't forget about the Old Man glitch or the Brock skip glitch in Red/Blue, or the Amazing Trainer glitches in Ruby/Sapphire, for example).
Anyway, I have a save file (which originally came from my LeafGreen cartridge) if you want to see any of this for yourself easily without having to start a new game:
Before I end this, I want to say… if you live in North America, happy 10th anniversary, FireRed and LeafGreen! That's right, they came out 10 years ago from today (September 9).