Apologies if this doesn't fit here, not sure where else to post something like this on lemmy
I think having gravity act like weather might be an interesting concept for a fantasy world, where each country has its own gravity patterns, some tend to be heavier some tend to be lighter, some are all over the place
For a few examples, there could be a desert with gravity so high you can get dragged down into the sand
Could be a country with gravity so low everyone uses personal aircraft that work like bicycles instead of land vehicles
Animals in higher gravity areas would have less dense bones, more muscle, etc and lower gravity would have far larger animals because they can support more weight
In a really high gravity area people might need exoskeletons to prevent long term damage
Mechanically, I’d modify the weather table in the DMG:
d20 Gravity
1-14 normal for the season/location
15-17 1d4 × 10 percent lighter than normal
18-20 1d4 × 10 percent heavier than normal
Example: a location that is 200% of normal (all weights doubled) could vary from 160% of normal to 240% of normal.