REGNUM is a long term Java 1.21.11 survival world where the map does not reset and players can pick their own path. It feels like vanilla SMP but with a medieval sandbox vibe where people build castles and set up lordships.
The main idea is minimal laws and maximum consequences. Staff only steps in for the important lines so most problems get handled by players through politics deals alliances or straight up PvP.
You can get into conflict and war with tools made for sieges and capturing enemies. Nights are harder too and there are balanced quality of life plugins. The community is small right now and they want more people who can handle rivalry without turning it into toxic harassment.