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Development: Hex Editing - Gen. 4 & 5

esperance

esperance

  • Poké Ball Great Ball Ultra Ball Premier Ball
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    • Seen Apr 7, 2025

    Generation 4 & 5 Hex Editing

    Okay, so I've been doing research into pretty much all DS Pokémon games, and I'm just creating a library for all of my research I've found.

    Pokemon Base Stats

    A pokémon's base stats are all the basic info of the pokémon, like the base HP, Attack, Special Abilities, etc.

    Diamond Info.

    Instead of writing this all out, please see this.

    Narc: "poketool/personal.narc"
    Location in ROM: 0x1C15A08 (Bulbasaur)
    Thanks to thethethethe.

    HeartGold Info.

    In Pokémon HeartGold, it follows the exact same format as found in Pokémon Diamond.

    Narc: "poketool/personal.narc"
    Location in ROM: 0x12B2840 (Bulbasaur)
    Thanks to me.


    Black (Japan) Info.

    In Pokémon Black, it uses a different format from Gen. 4. I'm still researching, so bear with me.

    Narc: "a/0/1/6"
    Location in ROM: 0x6F98554 (Bulbasaur)
    Thanks to me.

    Format Explained (Gen. 4)

    To explain the format, I will present an example, taken from HeartGold.
    The pokémon shown is Arceus.
    Code: 
    78 - HP (120)
78 - Attack (120)
78 - Defense (120)
78 - Speed (120)
78 - Special Attack (120)
78 - Special Defense (120)
00 - Type 1 (Normal)
00 - Type 2 (Normal)
03 - Catch Rate (3)
FF - Base XP (255)
03 - Effort Yield 1 - Not sure how works.
00 - Effort Yield 2 - Not sure how works.
0000 - Held Item 1 (None)
0000 - Held Item 2 (None)
FF - Gender Chance (Genderless)
78 - Steps for Egg to Hatch (121)*
00 - Base Happiness (0)
05 - Experience Type (1,250,000)
0F - Egg Type 1 (None)
0F - Egg Type 2 (None)
79 - Special Ability 1 (Multitype)
00 - Special Ability 2 (None)
00 - Safari Zone Run Chance (0)
07 - Pokedex Color (Gray)
00 - None (Padding)
00 - None (Padding)
7E - TM Switches 1-8
F7 - TM Switches 9-16
FF - TM Switches 17-24
F7 - TM Switches 25-32
FF - TM Switches 33-40
0E - TM Switches 41-48
5A - TM Switches 49-56
37 - TM Switches 57-64
EF - TM Switches 65-72
DD - TM Switches 73-80
7F - TM Switches 81-88
FE - TM Switches 89-92, HM 1-4
0F - HM 5-8
00 - None (Padding)
00 - None (Padding)
00 - None (Padding)
*To get actual cycles, add 1.

    How does the Gender Chance Work?

    To edit the gender chance, what you do is convert it to decimal, then do this:

    Data to Percent (Value * 100) / 254 = Percent (of Male).
    Precent to Value (Percent * 254) / 100 = Value.
    To get genderless pokémon, you make the value 0xFF (255).

    Format Explained (Gen. 5)

    Thanks to Awkward Squirtle for telling me about the different format.
    To explain this, I will post my current research for it by showing Bulbasaur (from Black).
    Code: 
    2D - HP
31 - Attack
31 - Defense
2D - Speed
41 - Special Attack
41 - Special Defense
0B - Type 1 (Grass)
03 - Type 2 (Poison)
2D - Catch Rate
00
00 - Effort Yield 1
01 - Effort Yield 2
0000 - Item 1
0000 - Item 2
00
00
1F - Gender Chance
14 - Steps for Egg to Hatch (in Cycles)
46
03 - Pokedex Color
01 - Egg Type 1
07 - Egg Type 2
41 - Special Ability 1 (Overgrow)
00 - Special Ability 2 (None)
22 - Dream World/Hidden Ability (Chlorophyll)
00
00
00
00
00
01
03 - Experience Type?
40 - Base XP
00 - Base XP 2?
07
00
45
00
20
87
39
84
08
9A
11
00
20
04
60
A2
04
00
00
00
01
00 - Padding
00 - Padding
00 - Padding

    Helpful Lists


    Pokemon (Gen 4)

    Thanks to Darthatron.
    Spoiler:


    Types (Gen 4)

    Thanks to thethethethe.
    Spoiler:


    Types (Gen. 5)

    Thanks to Awkward Squirtle.
    Spoiler:


    Items

    Thanks to gamefreakfatty.
    Spoiler:


    Experience Types

    Found by me.
    Spoiler:


    Egg Types

    Found by me.
    Spoiler:


    MORE COMING SOON! :D
     
    Last edited:
    It would be better simply to tell us what narc file the data would be in; the offsets are useless since the offsets of nearly EVERYTHING changes every time you modify a narc file.
     
    Chaos Rush said:
    It would be better simply to tell us what narc file the data would be in; the offsets are useless since the offsets of nearly EVERYTHING changes every time you modify a narc file.
    Click to expand...

    Good point. They are in the "personal.narc" in Diamond and HeartGold. I'm actually not sure about black.

    EDIT: Black's pokemon data is in the narc "a/0/1/6"
     
    Last edited:
    Gen 5 doesn't have a ??? type; 09 is Fire etc. Effort yield is as simple as two bits per stat, I believe (12 bits in total).

    B/W use a different Pokémon data format; this change was responsible for Serebii originally getting the Pokédex data wrong on his site (IIRC, the types were wrong because of the above change, for example). B/W use two bytes for the base experience, and have a third ability byte (I'm pretty sure there's more, but I can't remember them off the top of my head). Also, the level-up move list is different, as each move is now four bytes rather than two (though you haven't covered this). The B/W move list is identical to the D/P/Pt list, but with the new moves added on the end; so is the B/W ability list. However, the items list was completely revamped in B/W, so your item codes won't work.
     
    Awkward Squirtle said:
    Gen 5 doesn't have a ??? type; 09 is Fire etc. Effort yield is as simple as two bits per stat, I believe (12 bits in total).

    B/W use a different Pokémon data format; this change was responsible for Serebii originally getting the Pokédex data wrong on his site (IIRC, the types were wrong because of the above change, for example). B/W use two bytes for the base experience, and have a third ability byte (I'm pretty sure there's more, but I can't remember them off the top of my head). Also, the level-up move list is different, as each move is now four bytes rather than two (though you haven't covered this). The B/W move list is identical to the D/P/Pt list, but with the new moves added on the end; so is the B/W ability list. However, the items list was completely revamped in B/W, so your item codes won't work.
    Click to expand...

    Thank you for the information, I'll research the format right away.

    Team Fail said:
    There's also a hex list for music. Using the list below, convert it to hex and reverse it, then you can insert it where you need. This list correlates with the AR Code to modify music (And this is the translated German version!)

    DP:
    Spoiler:


    Others (might) come soon!
    Click to expand...

    This looks useful, thanks!
     
    I tried to change the experience type of some pokemon today and noticed that experience type byte is wrong the Gen 5 Format. It should be the byte that is now wrongly labeled as Pokédex Color.
    I confirmed this with in-game testing.

    Format Explained (Gen. 5)

    Thanks to Awkward Squirtle for telling me about the different format.
    To explain this, I will post my current research for it by showing Bulbasaur (from Black).
    Code:

    2D - HP 31 - Attack 31 - Defense 2D - Speed 41 - Special Attack 41 - Special Defense 0B - Type 1 (Grass) 03 - Type 2 (Poison) 2D - Catch Rate 00 00 - Effort Yield 1 01 - Effort Yield 2 0000 - Item 1 0000 - Item 2 00 00 1F - Gender Chance 14 - Steps for Egg to Hatch (in Cycles) 46 03 - Pokedex Color Exp. Type 01 - Egg Type 1 07 - Egg Type 2 41 - Special Ability 1 (Overgrow) 00 - Special Ability 2 (None) 22 - Dream World/Hidden Ability (Chlorophyll) 00 00 00 00 00 01 03 - Experience Type? 40 - Base XP 00 - Base XP 2? 07 00 45 00 20 87 39 84 08 9A 11 00 20 04 60 A2 04 00 00 00 01 00 - Padding 00 - Padding 00 - Padding
     
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