Origins: Player Scale
What's this?
This datapack adds an independent Origin layer that allows players to choose one of 6 sizes, or choose the standard Minecraft size.
You can play whatever classic or addon origin you like, in addition to picking a custom size.
The available sizes are: Normal; Small; Very Small; Tiny; Big; Very Big; Giant.
You can view all the Origin cards in Modrinth's gallery; they include flavor text, but not exact stat bonuses.
All scaling is applied with multipliers, which should help with compatibility.
Tested on 1.18.2 through 1.20.2, but as a datapack it's likely to work on most if not all Minecraft versions.
1.20.2 is experiencing some bugs with its dependencies, as of 2023-12-8. This isn't the only datapack affected; hopefully the issues are resolved soon!
In general...
Small folk fit into smaller areas, take less fall damage, and are less visible to enemies. Being small has no significant downside.
Large folk have trouble with typical buildings. As a tradeoff, they are more mobile, with better speed, jump height, step height, and reach. With greater bulk comes greater knockback and knockback resistance, and a small amount of extra health per size. (As an example, Giant receives 6 extra hearts, and is a cumbersome 4 blocks tall.)