/r/CivCraft is a modded Reddit Minecraft server that is extremely populated.

Like Rust, players spawn at a random spot on a huge map and are left to their own devices to create towns, civilizations, and governments.

There's no "faction" system, but buildings can be reinforced with material.

You can reinforce every block you place with either Stone, Iron or Diamond.

Stone will make the block have to be broken 25 times, Iron makes it 900, and Diamond 1800.

This means if you reinforce a structure with Diamond it can end up taking hours of constant mining (plus repairing picks) to break. Most people store their valuables in what is known as DRO (Diamond Reinforced Obsidian) vaults. It takes around 2.5 hours of nonstop mining just 2 block of DRO.

This is a great system because it gives new significant worth to Stone, Iron and Diamond.

Anyway thanks for reading, a system like this would make Rust very balanced. You should check out the subreddit and it's wiki. The entire server is fascinating.