We often associate Pokémon FireRed et Pokemon Leaf Green old cheat codes and duplication glitches, or hundreds of resets for a chromatic starter. Many players still think that a Mewtwo shiny necessarily requires Action Replay or emulator.
Good news: GBA cartridges like the Switch port hide a completely legal trick, the manipulation of the RNG Pokémon Fire Red Leaf Green. By finely controlling the internal random number generator, you can target almost any Pokémon without ever changing your save.
RNG Pokémon Fire Red Leaf Green: why is this tip not considered cheating?
The RNG, for Random Number Generator, is the sequence of numbers that the game uses for everything that seems random: encounters, IV, nature, shiny. In Rouge Feu Vert Feuille, a seed is calculated at startup and then advanced each frame. RNG manipulation simply involves knowing which seeds give which Pokémon, and pressing A at the right time. No code is injected, nothing is edited, you just exploit intended behavior.
Result: one Mewtwo obtained thus is identical, to the nearest bit, to a Mewtwo fell by chance. The shiny hunter communities classify it as “full legitimate”. Conversely, ACE or cheat codes modify the ROM or the save, which is no longer the case here.
How to use Pokémon FireRed and LeafGreen’s RNG to target the ideal Pokémon?
It all starts with your secret ID, the SID, hidden behind the Trainer ID displayed on the Trainer card. To find it without cheating, you capture a Pokémon, note its nature, gender and statistics, raise it a few levels, then enter all this information into a Generation 3 IV calculator. With PokeFinder and the “IVs to PID” function, it is then possible to deduce your SID from these IVs and your Trainer ID.
Once the SID is known, you go to Ten Lines, a database of seeds tested for the RNG Pokémon Fire Red Leaf Green. You filter the species, nature, sex, shiny status and IV range, whether for a starter, Élovea fossil or a legendary one. The site then provides you with the precise timings to aim for, which you reproduce with EonTimer: a first counter for pressing A on the title screen, a second just before generating the Pokémon. Between each attempt, you must completely close the game to start from the same seed.
Which Pokémon to obtain thanks to the Fire Red Leaf Green RNG manipulation, and who is it for?
Mastered, this trick opens almost the entire Pokédex: shiny starters, Mewtwo chromatic, legendary birds with good IVs, Élove ideal or Dratini dreamed of fishing. On the other hand, aiming for several near-perfect pressures requires practice and a PC at hand.
