HGSS : Expand the type chart without breaking the code (+ some other things)

Hi everyone.
I'm MeroMero (yes the same MeroMero from Smogon)

I finally jumped the gun and joined PokéCommunity just so I could share my findings.

Be ready though, this post is going to be quite long.

Some notes:
When an offset is followed by an asterisk (*) ,it means that the offset differs between different regions (and sometimes between games of the same region).
Unless specified otherwise, bytes' endianness is usually little-endian.

EDIT: Type-chart updated


Changing the template's color for ???-typed moves on the bottom screen to suit Fairy-type moves better.

This one is easy:

• Decompress overlay9_0006.bin
• Go to offset 0×290
• Change this:

• Into this:

The colors will fit the Fairy-type much more now.



Editing the Incenses-babies.

• Decompress arm9.bin
• Go to offset 0×FF4AE*
• You should see this:

Format is BB BB II II DD DD.
BB BB is the baby produced when at least one parent holds the corresponding item.
II II is the item that at least one parent has to hold.
DD DD is the default baby when none of the parent holds the corresponding item.

For example we're going to dissect the 7th row, shall we?
96 01 is a Pokémon ID.
Invert the 2 bytes and you get 01 96.
Converting from base 16 to base 10 we get 406.
Oh, it's Budew!
This is the same principle with the item ID and the default baby ID.
Item ID: 3E 01 => 01 3E => 318 => Rose Incense
Default baby ID: 3B 01 => 01 3B => 315 => Roselia

The instruction is as follows: If at least one of the Parents hold the Rose Incense, Budew will hatch from the egg, otherwise Roselia hatch from the egg.

So if you have understood, it means we basically have to replace all 9 instances of DD DD by their corresponding BB BB.

• Change the previous bytes and you should obtain this:

Neat, now how about you go and hatch that Budew without a Rose Incense, hum?

* Regions' differences:Heal Bell ignores the Soundproof's check and behaves exactly like Aromatherapy

Disclaimer: Read all the paragraph before attempting any manipulation.

• Decompress overlay9_0012.bin
• Go to the very bottom of the file
• You should see something like that:

Q: What are those?
A: Those are the very moves blocked by Soundproof.

Each move is 2 bytes long, for example let's try this one: 30 01.
Invert the 2 bytes and you get 01 30.
Now convert from hex to decimal and you get 304.
304 is the ID number for the move Hyper Voice!

Well what move are we trying to break already? Oh yes, Heal Bell.
So the move Heal Bell has been assigned the ID number 215.
Okay 215 in hexadecimal is D7, since moves are 2 bytes long instead let's go with 00 D7.
Invert the 2 bytes and you get D7 00.
Time to go and check against the previous string…
…
…
HEY! But there's no bytes equal to D7 00 in there!

Explanation: Actually this string lists the moves blocked by an opponent's Soundproof! Have you ever tried to use Heal Bell against that Exploud? Believe it or not but it will work.
When it comes to the move Heal Bell, the game will instead perform a check against all of your team members' abilities, and if a Pokémon affected by a major status condition happens to have Soundproof, it will not be healed.

Tough luck, huh? But this will come to an end with those simple-to-follow steps.

• Decompress overlay9_0012.bin
• Go to offset 0×98A0* and change the value D7 into 00
• Do the same at offset 0×21ADE*
• Go to offset 0×98B0* and change the value 2B into FF (anything between 7C and FF included will do the trick)
• Do the same at offset 0×9906* and offset 0×21AE4*

Offset 0×98A0 is the check for Heal Bell's execution for the Pokémon on the battlefield, on the side of the Heal Bell's user.
Offset 0×21ADE is the check for Heal Bell's execution for the remaining team members of the Heal Bell's user team.

Offset 0×98B0 is the check for Soundproof against the Heal Bell's user.
Offset 0×9906 is the check for Soundproof against the teammate of the Heal Bell's user (Double battle only).
Offset 0×21AE4 is the check for Soundproof against the remaining team members of the Heal Bell user's team.

Basically the new instruction is: check if [Pokémon] used move with ID 0 and check for every instance of ability with ID 255.

You shouldn't replace 2B by 00, because the ability with ID number 0 is used in-game when an ability gets cancelled (Gastro Acid comes to mind), whereas you can replace D7 by 00 since there is no legitimate way to get the move with ID number 0.

* Regions' differences:



Complete type chart


[FONT=&quot]This is the type-chart:[/FONT]

[FONT=&quot]

Here is its format :
AA DD EE
_AA : attack type
_DD : defender type
_EE : effectiveness
those 3 bytes are repeated consecutively for basically each type, and the table will end at the first occurrence of AA DD equal to FF FF.

AA and DD can take one of the following values :
_0×00 : Normal
_0×01 : Fighting
_0×02 : Flying
_0×03 : Poison
_0×04 : Ground
_0×05 : Rock
_0×06 : Bug
_0×07 : Ghost
_0×08 : Steel
_0×09 : ???
_0×0A : Fire
_0×0B : Water
_0×0C : Grass
_0×0D : Electric
_0×0E : Psychic
_0×0F : Ice
_0×10 : Dragon
_0×11 : Dark

EE can take one of these 4 values :
_0×00 : ineffective
_0×05 : not very effective
_0×0A : normal damage
_0×14 : super effective

As you have guessed, EE is actually a multiplier, but before the effect is applied, EE is divided by 10, thus the origin of the coefficients ×0, ×0.5, ×1 and ×2 !

But there's a first problem, if you try to search for 00 05 05 00 08 05 0A 0A 05, etc. in the ROM, your hex editor of choice will return no results!
This is because the overlay that contains the table (overlay 12 here) is LZ-compressed[FONT=&quot] (all overlays are compressed in HGSS anyways).[/FONT]
Decompress it with Crystal Tile 2 for example.

Okay now you search through the decompressed overlay 12 with your hex editor, and now you have found the string, great; but there's a second problem!
Look at the table, there's no EE bytes whose value is equal to 0×0A!
That's because 0A is the default multiplier in Gen 4 Pokémon games, which is why ???-typed moves/Pokémon deal/take neutral damage to/from everything. But unlike Gen 2 and Gen 3, thanks to the Physical-Special split, ???-typed moves are actually able to deal damage greater than 1HP (read real damage).
How is it going to affect us?
Well you're going to have a hard time if you want to port the Fairy type effectiveness in HGSS (for the sake of an example).
If you try to add (DON'T !) even only one more relationship, once you get into a fight you will break the game since the arm9 code will read wrong instructions from everything in the overlay 12 that come after the type table…


How to trick the game then?
First you have to understand how the game works:
Let's say you have 2 main states in Pokémon games, the overworld and the fights.
The game needs to load the following overlays for the overworld: 1, 2, 3 and 27 (Group 1)
And it needs to load these for the fights : 6, 7, 10, 12, and 18 (Group 2)
Actually the overlay 10 is loaded every time you get to choose your action, the overlay 7 when you have chosen said action (and initially at the beginning of the fight too).

Once you press continue on the menu screen, the game will load the group 1, and when you get in a fight, it will load the group 2, once you are finished with your fight the game will load again the group 1, etc.
You can see that with the RAM Viewer around address 0×021D0E00 for those who are curious
It's something like this:[/FONT]
[FONT=&quot]Overworld:[/FONT]
[FONT=&quot]Fight:[/FONT]
[FONT=&quot]

If you parse through the RAM, you'll see that when the overlays from one group are loaded, the previous overlays who happened to be there will be overwritten.

The trick here is to find a place in the RAM that is not used during the fights and that could be used to fit in the new table.
And such an area exists!
It just so happen that overlay 18 and overlay 1 have the same offset in the RAM, but ovl_1 is much longer than ovl_18! That's exactly what we need.

What does it means? It basically means that the ovl_1 leftovers is basically free space during the fights!


Modus Operandi

Step 1
Open your Pokémon HeartGold or Pokémon SoulSilver ROM in Crystal Tile 2.[/FONT]
[FONT=&quot]

Step 2
Click the NDS icon (or alternatively click Ctrl+N).[/FONT]
[FONT=&quot]
Expand the window if necessary.

Step 3
Right-click on overlay9_0012.bin and click Extract (not Export !), this will actually decompress the overlay.[/FONT]
[FONT=&quot]
Step 4
Do the same for overlay9_0018.bin.

Step 5
Open both decompressed files in a hex editor.

Step 6
Add your improved type-chart at the end of overlay9_0018.bin[/FONT]
[FONT=&quot]

I advise you to make a full chart with all 324 relationships from the get-go, so that if you want to change something, you won't have to go through all the trouble again.
Or you can take mine, which is up to date with the relationships according to Gen 6 :[/FONT]
[FONT=&quot]

Step 7
In overlay_0012:
[/FONT]

• [FONT=&quot]search for 7CCC2602* and change it for 60BE1F02* (4 occurrences)[/FONT]
• [FONT=&quot]search for 7DCC2602* and change it for 61BE1F02* (3 occurrences)[/FONT]
• [FONT=&quot]search for 7ECC2602* and change it for 62BE1F02* (3 occurrences)[/FONT]

[FONT=&quot]
As you have guessed, the pointers will point to the type table, what you did here is relocating the pointers to the new and (admittedly) more complete table.

Step 8
Save both files and close your hex editor.

Step 9
Back to Crystal Tile, right-click on overlay_0012.bin and click Compression, this will actually import the LZ-compressed of your file back into the ROM.[/FONT]
[FONT=&quot]

Step 10
Do the same for overlay_0018.bin, but be careful now the file is too large to be contained between ovl_17 and ovl_19 even when compressed ! But do not fret, Crystal Tile will take care of that for you.[/FONT]
[FONT=&quot]
Just click OK.

Step 11
Close Crystal Tile 2, and now your ROM is ready.

Want to make Poison super-effective against Water ? Sure thing mate.
Want to make Ice resistant to Dragon ? Knock yourself out !
Want to add all the Fairy type relationships ? That's the reason that drove me to think outside the box and find a way to present you this.



[FONT=&quot]W[FONT=&quot]ow ! And I'm still not done, but other[FONT=&quot]s discoveries will be for another time, I[FONT=&quot] think those will take eno[FONT=&quot]ugh of you[FONT=&quot]r time to swallow.
[FONT=&quot]
[FONT=&quot]Other discoveries include:
[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Adding a[FONT=&quot] functional item (why not, the Pixie Plate)[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Adding an item's effect I[FONT=&quot]D [/FONT][/FONT]to the list of [FONT=&quot][FONT=&quot]×1.2 [/FONT]type-en[FONT=&quot]hancer [/FONT]items[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Edit the move Judgment so it takes into account the Fairy-Type, yes the case for type 9 [FONT=&quot]is not taken into account in the move[FONT=&quot]'s code[/FONT][/FONT]
  [/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Ed[FONT=&quot]it [/FONT][/FONT][/FONT]Pokémon coordinates and shadow on the battle[FONT=&quot]fiel[FONT=&quot]d (not by me)[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

[FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]
[FONT=&quot]Another notes:
[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Th[FONT=&quot]e[FONT=&quot] co[FONT=&quot]de for evolution metho[FONT=&quot]ds 18, 19 and 1A [FONT=&quot]was scrapped in HGSS[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]Explorer Kit was dummied out in HGSS[/FONT], it will appea[FONT=&quot]r as a blank item[/FONT]
  [/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
• [FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot][FONT=&quot]There's [FONT=&quot]N[FONT=&quot]O wa[FONT=&quot]y to legitimately make Arceus stay in its [FONT=&quot]??? form in gen IV games without [FONT=&quot]modifying the code,[FONT=&quot] in the code the case for type [FONT=&quot]9 (???-type) is simply non-existant, plus even if you could get it you would have to modify the move Ju[FONT=&quot]dgment too.[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

[FONT=&quot]So, what do you think?[/FONT]

The discovery of magic, and why I didn't see a bin file

i want know where have the overlay9_0006.bin or how can Decompress get it

This is huge!. Is it possible to change the ???-type icon to the pinky Fairy one. If yes, can you show us how to do that.
Thank you for sharing. I hope you will post more of your dicoveries soon.

I don't understand.

For some reason, after I make the changes the save option for Crystal Tiles is greyed out and I can't save. Is there something I'm not doing correctly. I was trying to edit a romhack if that helps.

DSg077 said:

For some reason, after I make the changes the save option for Crystal Tiles is greyed out and I can't save. Is there something I'm not doing correctly. I was trying to edit a romhack if that helps.

Click to expand...

Actually it's simple, if you modified your ROM just try to close CrystalTile and it should bring up a confirmation window (twice if you click the uppermost cross), then click Yes.

When you say: [FONT=&quot]Add your improved type-chart at the end of overlay9_0018.bin
[FONT=&quot]Do you mean [FONT=&quot]really add them [FONT=&quot]therefore extending[FONT=&quot] the bytes used or adding them by modifying the bytes placed [FONT=&quot]near the end? It's kinda vague sorry if I don[FONT=&quot]'t get [FONT=&quot]it at all.[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
[/FONT]

May someone just upload HeartGold with Fairy Type in game I don't want to download SunGold (Not because it's a bad hack just because I want a HeartGold with just Fairy Type added and not everything changed)

Thank you for the wonderful tutorial, Meromero. It was quite easy to follow and I managed to insert everything and have it function. However, I have a question. Where do I find the type icons, so I may add the fairy icon? I combed through all of the "a" folders with CrystalTile, but I can't seem to find them at all.
EDIT: I ended up finding it using Desmume's palette function and by searching through the hex. For anyone in the future who is curious: It's located in the a/0/0/8 file. There's another one in "batt_obj.narc" located in the pbr folder, but those are just holdovers from D/P/P and will do nothing if you change it.

Can you also make a guide to restore the slot machines in HG/SS? The code should still exists in the international roms, the graphic resource file is cleared but still existing. Maybe should be funny create a new script command (or use an unused entry) to keep both slots and Voltorb flip. You seem very able to work with the asm files.

Thank you very much for this tutorial !

However there is actually a typo in the type chart, which I found last month:
07000007010A07020A07030A07040A07050A07060A07071407080A07090A070A0A070B0A070C0A070D0A070E14070F0A07100507110A
07 10 05 07 11 0A = Ghost (07) is ineffective to Dragon (10) , while neutral to Dark (11)
The correct relationship should be 07 10 0A 07 11 05