Pokemon Fire Red Exp Multiplier X2 Link

00 00 47 70 to:

0x08023C20: 4770 bx lr (returns)

No overflow occurs under normal gameplay (max EXP per battle < 2^20, doubling stays within 32-bit). pokemon fire red exp multiplier x2

1. Objective To modify the game code of Pokémon Fire Red (USA, Rev 1) so that any experience points (EXP) earned after a battle are automatically doubled before being added to a Pokémon’s total EXP.

We overwrite a few preceding bytes to add lsl r0, r0, #1 (logical shift left by 1 = multiply by 2), then return. 00 00 47 70 to: 0x08023C20: 4770 bx

| Pokémon defeated | Base EXP | Normal gain | With 2× patch | |----------------|----------|-------------|----------------| | Rattata (Lv.3) | 45 | 45 | 90 | | Pidgey (Lv.5) | 55 | 55 | 110 | | Trainer battle | 400 | 400 | 800 |

Original bytes: 00 00 47 70 Patch to: 40 00 47 70 We overwrite a few preceding bytes to add

At the end of the EXP calculation, before the function returns, we insert a left-shift (multiplication by 2) of the value in r0 .