Research: EM & FR - Natures

Here's some information on how to change the effect of nature.

Starting with offset 252B48 (fire red) or offset 31E818 (Emerald), you will find the nature effects table.

Each nature consists of 5 bytes (Atk/Def/Speed/Sp.Atk/Sp.Def).

The value "00" is a neutral value, nor does it increase or decrease any statistics.
The value "01" is responsible for increasing certain statistics.
The value "FF" is responsible for decreasing certain statistics.

The first nature of the table consists of 00 00 00 00 00 (Nature Hardy).
If I want it to be a physical offensive nature, I will add "01" in the first byte, and "FF" in the 4th byte (01 00 00 FF 00).
So Hardy nature will have the same effect as Adamant Nature.


If I do otherwise, nature will have the effect of Modest Nature (FF 00 00 01 00).


There is no secret or difficulties in understanding how this works.
Feel free to modify the effects of natures at will in your rom hack.

Hey @Fansity.
Your thread was approved, but the images are not displayed correctly. Fixing them will help!

So, I'm guessing that with this, you could create "inflated" natures, that could raise more stats at once and natures that don't have any drawbacks

Upsurge said:

Hey @Fansity.
Your thread was approved, but the images are not displayed correctly. Fixing them will help!

Click to expand...

Fixed, thanks for the warning.

Manekimoney said:

So, I'm guessing that with this, you could create "inflated" natures, that could raise more stats at once and natures that don't have any drawbacks

Click to expand...

That's right, you can do this. For example, I can create a Nature that increases Atk and Sp.Atk without reducing any other statistics. The image below proves it.
Before:

After:

In the example of the image, I changed Nature Hardy, causing it to up the Atk and Sp.Atk without reducing Defense, Sp.Def, or Speed.