I'm trying to change the rarity by using a datapack and came across a problem that even if I set common weight to 500 and rare weight to 0, I'll still get rare sometimes. Also tried change the quality (i don't know what it is exactly), but everything remains the same. Datapack is working, also changed rules of rarity and it worked.

How can I change rarity weight?
Here my datapack
test.zip

Zipped a folder, sorry

Editing the rarity weights does work, but rarity weights are not the sole arbiter of what rarities get placed into the world, since some objects specify a minimum rarity they may generate at (1.20) or a valid set of potential rarities (1.21).

Usually that would be the affix loot entries, or the affix convert rarities (1.20) set in the config. You'll need to make an even broader datapack to setup the rarity generation in the desired fashion.

Thank you for quick answer!

I was writing this in the dead of night, after a long search for this feature like a madman and did not specify a couple of important things. It's 1.20.1 and I don't want to completely remove the rarity from overworld, but I want to make much more difficult to find item with a higher rarity. Rarity weight of 0 is just for test.

In fact, I plan to leave only the transformation items from loot_tables by default, and make the same thing with rarities for gems.

Ideally, I would also increase the chances of higher rarity with distance (like for auto-leveling mob mod), I might have thought that if there was a function for turning item into a certain rarity item or gem for loot_table, not like generating random item with random rarity, then I could rewrite the drop of rarities in chests (i thing like rewrite every loot_table).

I really like this mod, but it's very dynamic and there are a lot of values on the items. I planing a very slow game progress, and therefore I want to do this.