Generation I move effects 4A and 4B - Page 1
On The Cutting Room Floor on the unused move data sub-page, there are entries on the unused move effect section for move 4A: "10.2% chance of lowering a non-existent glitch stat by 1 stage, which effectively does nothing." and 4B: "10.2% chance of lowering a non-existent glitch stat by 1 stage, which effectively does nothing."
Is this behaviour due to a glitch or was another stat (such as Special Defense) initially planned in Pokémon RBY?
It's unclear whether this was supposed to be intended behavior or not. Here is a part of the move effect table:
[tt]dw PayDayEffect ; PAY_DAY_EFFECT
dw $0000 ; SWIFT_EFFECT
dw StatModifierDownEffect ; ATTACK_DOWN_SIDE_EFFECT
dw StatModifierDownEffect ; DEFENSE_DOWN_SIDE_EFFECT
dw StatModifierDownEffect ; SPEED_DOWN_SIDE_EFFECT
dw StatModifierDownEffect ; SPECIAL_DOWN_SIDE_EFFECT
dw StatModifierDownEffect ; unused effect (0x48)
dw StatModifierDownEffect ; unused effect (0x49)
dw StatModifierDownEffect ; unused effect (0x4A)
dw StatModifierDownEffect ; unused effect (0x4B)
dw ConfusionSideEffect ; CONFUSION_SIDE_EFFECT
dw TwoToFiveAttacksEffect ; TWINEEDLE_EFFECT
dw $0000 ; unused effect[/tt]
The pointers for those glitch effects do not come from any out of bounds data - the programmers who created this table explicitly added 8 effects responsible for lowering stats. The remaining two entries in the table ended up as placeholders. So there might have been plans for extra two stats in the game (Special Attack and Special Defense?). However, there are no corresponding unused entries for other stat-related effects (lowering by 2 stages, raising by 1 stage, raising by 2 stages).
The actual behavior of the effects looks glitchy because the stat names are taken from an out of bounds location. But in fact, aside from the glitchy message, the subroutines responsible for handling stat changes are properly adapted to work with stat indices from 0 to 7.
Interestingly enough, two bytes in RAM located right after the stat changes table are unused, as if there's actually space reserved for two additional stats.
As it stands, all of this could still be accidental. There's no conclusive proof that the two mysterious unused stats were actually intended to be used.
I see, interesting. Thanks a lot for the information TheZZAZZGlitch! It would have been nice if Special Attack and Special Defense made it to Generation I, although I wonder if that would end up nerfing Pokémon like Chansey, Gengar.