I found a modded server called Iperios that runs on All the Mods 10 version 5.5. The main idea is nations where players can make their own group with a government plus laws and ranks.
If you do not want to start your own nation you can join one that already exists. To get in you join their Discord and ask for whitelist then check the new player info channel for what to do next.
After you get whitelisted a staff member helps you and gives a beginner kit so you can start playing. You need the ATM10 modpack installed on version 5.5 to join.
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