Edit GP Rain damage

This is the only other code relevant to GP Rain.

Code:

GP Rain

C2/1907: BB           TYX
C2/1908: 20 8A 29     JSR $298A      (Load command data, and clear special effect,
                                      magic power, etc.)
C2/190B: EE A6 11     INC $11A6      (Set spell power to 1)
C2/190E: A9 60        LDA #$60
C2/1910: 0C A2 11     TSB $11A2      (Set ignore defense, no split damage)
C2/1913: 9C 14 34     STZ $3414      (Skip damage modification)
C2/1916: E0 08        CPX #$08
C2/1918: 90 05        BCC $191F      (branch if character)
C2/191A: A9 05        LDA #$05
C2/191C: 8D 12 34     STA $3412      (will display "GP Rain" atop screen.
                                      differentiated from "Health" and "Shock"
                                      by $B5 holding command 18h in this case.)
C2/191F: A9 A2        LDA #$A2
C2/1921: 8D A9 11     STA $11A9      (Store GP Rain in special effect)
C2/1924: 4C 7B 31     JMP $317B      (entity executes one hit)

So Madsiur is correct. When the GP Rain command is selected, an animation override is put in place (making the character throw coins instead of using their normal fight movement), base battle power is set to 1 and set to be unmodified (to ensure that the character's stats do not influence the attack), and then battle power is set to Level * 30. The game deducts a comparable quantity of gold from the party's inventory when the attack is attempted.

What Madsiur described is thus the only good way to tweak GP Rain: change the amount of money that it costs per level. Otherwise you'd have to rewrite the special effect to allow for a multiplier or a flat base damage.


EDIT: Keep in mind $1E is a signed hex value; if you set it any higher than $80 (128 gold per level) the game will interpret it as a negative number and will either crash or do something erratic like heal the enemies and give your party gold for it.