You start naked and terrified. Rust is a massive online sandbox that mixes the Minecraft free-building design with a DayZ setting. You start with nothing but a rock, 2 bandages, a torch, and your naked ass. You're dropped onto a server with other players, collecting materials, building shelters, crafting clothing and making weapons. Rust is also PvP, so you will be killed, multiple times, and looted, by players choosing the bandit's life instead of the pioneer's. You respawn with nothing, so you better store your valuable items and materials in storage boxes, or chests, but those can be robbed too, so you need to build a house to keep the treasure in. Doors in the game can only be opened by the player who built them, so you're relatively safe inside structures that you've built. However, there are players who advance enough to craft C4, who can blow your stupid door off and get to you.
What results is a game that is truly terrifying. During the game's nighttime, advanced players grab their guns, and raid all of the pitiful wooden shelters that the n00bs are building. For players without guns (and they are difficult to make), staying inside is a necessity at night. You can't see anything without a torch, and lighting a torch lets every advanced player know exactly where you are from miles away. Resources are so time consuming to farm, and valuable weapons/armor are so expensive to acquire and maintain, that killing other players for their shit is just too tempting. Most players will try to kill you on sight, and if you're naked with a rock, you have absolutely no chance.
What's great about Rust is that the game didn't make the rules. The developers provided a sandbox, and made materials extremely valuable. It was us, the players, who made the in-game Rust society one of overwhelming paranoia, adopting a "don't trust anyone regardless of circumstance" mentality. I spent most of my night here, in my little shack, guarding the door, planning my next day. I need to kill sheep to get animal fat and cloth, enough to make a sleeping bag and some low-grade fuel. Sleeping bags are spawn points, and having one in the house is the only way to guarantee that you can spawn inside with your stuff, as long as nobody raided your stash and blew off your door while you were logged out.
I got lost in the middle of the night and was hunted by a player with a rifle who kept whispering into his mic, "I'm going to kill you taco" or, "Why are you running taco?". I found a pair of radiation-proof pants and was then chased to the top of a giant boulder and beaten to death by a naked man with a hatchet. Rust is a land of chaos and bandits right now, but there are almost 40,000 players, and I've heard on the Steam message boards that some players are building towns, with walls, and leaders....