I actually thought about something similar a while back, specifically with a magic system where one player creates puzzles to prevent griefing, sort of like wards or charms in fantasy, and attackers have to solve them to be able to get to the loot and get damaged by the elements if they fail, in a type of Rust PvP setup. It ended up way more difficult when I tried to make a prototype, mostly because you have to allow for a wide range of possibilities while also allowing a wide range of difficulty, but this is something I think would be fun to play, it might just be really hard to implement and balance.