how to change the skill "possess"

If I were to change "Possess" into casting the spell "Storm" like in The Eternal Crystals how would I do it? Because all the values that I put in to supposedly represent "Storm" keep crashing my ROM.

Madsiur explains exactly how to do on page 2 in this thread.
Copy what he did there and it should work.

I tried the ways shown here, but for some reason the original values for possess aren't the same as the values I have:

Code:

C2/17E5:  82
C2/17E6:  ED AA 7B
C2/17E9:  E2 20
C2/17EB:  E4 1E F0
C2/17EE:  48 C2
C2/17F0:  20 BF 34
C2/17F3:  86 ED 85

Your ROM appears to have a header, so either remove it via an option in the hex editor, or add +200 to the address to get there (C2/19E5). Alternatively you could do a hex search for the bytes (BB 20 C1 19 etc.) to find it.

You can tell if your ROM is headered if there are 200 $00's at C0/0000 - C0/00200

Okay, I have encountered another problem:

I want to change the command "Capture" into casting the spell, "Flare Star". But whenever I run into a battle, the monster always cast Flare Star.

I would like to fix this while also still having Flare Star assigned to the Capture Command

But whenever I run into a battle, the monster always cast Flare Star.

It would be a good thing you post your custum capture code so we can check what is wrong with it...

My Apologies, I was in a hurry last time. But here's the Original code:

Code:

C2/1610: C0 08        CPY #$08       (Capture enters here)
C2/1612: B0 07        BCS $161B      (branch if monster)
C2/1614: B9 D8 3E     LDA $3ED8,Y    (Which character it is)
C2/1617: C9 0D        CMP #$0D
C2/1619: F0 20        BEQ $163B      (branch if Umaro)
C2/161B: BB           TYX
C2/161C: BD 58 3C     LDA $3C58,X
C2/161F: 4A           LSR
C2/1620: A9 01        LDA #$01
C2/1622: 90 02        BCC $1626      (branch if no offering)
C2/1624: A9 07        LDA #$07
C2/1626: 8D 70 3A     STA $3A70      (# of attacks)
C2/1629: 20 4D 5A     JSR $5A4D      (Remove dead and hidden targets)
C2/162C: 20 65 38     JSR $3865      (depending on $3415, copy targets into backup targets
                                      and add to "already hit targets" list, or copy backup
                                      targets into targets.)
C2/162F: A9 02        LDA #$02
C2/1631: 14 B2        TRB $B2        (clear no critical & ignore true knight)
C2/1633: A5 B5        LDA $B5
C2/1635: 8D 13 34     STA $3413      (save backup command [Fight or Capture].  used for
                                      multi-strike turns where a spell is cast by a weapon,
                                      thus overwriting the command #.)
C2/1638: 4C 7B 31     JMP $317B      (entity executes one hit (loops for multiple-strike
                                      attack))

and my code:

Code:

C2/1610: A9 C6                  LDA#C6              (Flare Star)
C2/1612: 85 B6           STA $B6        (Set spell/animation)
C2/1614: A9 02           LDA #$02       (Magic)
C2/1616: 4C 69 64        JMP $6469      (jump to subroutine C2/6469)

C2/6469: 85 B5           STA $B5        (Set command)
C2/6471:  4C 5F 17        JMP $175F      (jump to subroutine C2/175F)

The fight command eventually reaches C2/1610 as well and as it is now you're jumping over the "Character executing one hit" routine at C2/317B as well as at least one other routine. You also forcing magic as the command to execute for every character.

I suggest you put the following at C2/1635:

Code:

20 69 64       JSR $6469

Then at C2/6469:

Code:

C2/6469: C9 06    CMP #$06
C2/646B: D0 08    BNE $6475 (branch if not capture)
C2/646D: A9 C6    LDA #$C6
C2/646F: 85 B6    STA $B6
C2/6471: A9 02    LDA #$02
C2/6473: 85 B5    STA $B5   (in case $B5 is used elsewhere...)
C2/6475: 8D 13 34 STA $3413
C2/6478: 60       RTS

I haven't tested this though, there might be issues I haven't foreseen.

Is there any way to bind the effect of an item to a command (like the Offering, Magicite, Super Ball, Etc.)

I think it would be a Fun Thing to have Phoenix Downs be Useless, and instead, upon Character Death, have them swap places with a Fight-less Ghost Character, and only a Successful "Possess" would revive the Character.

I Suppose Life 3 would, perhaps, create an Interesting Situation then.