Originally posted by JinKo82:

is their griefing like ark? i dont want to spend hours building if im just going to get offline raided.

The worlds are locked with passwords so randoms can't join just any world uninvited,

The game is designed to be coop with friends (or solo) which means you can play together with up to 9 friends (people you trust).

As solsiva mentioned, there are wards, which are supposed to sound an alarm if someone is attempting to break into your base and or chests... The ward is not some sort of insurance against raiding as it only slows someone down slightly... If they want in and no one stops them, they CAN break in and steal your stuff. The ward does not stop that... Also note that you can't kill or be killed by other players unless both parties have clicked the friendly-fire button, so there's really no way to defend your base / stuff by attempting to kill the would-be robber(s).

Bottom line is that you should only give your password, and play with people you trust, otherwise you run the risk of griefing.

Another point to make here is that only dedicated servers run 24/7 and can be played while the "owner" is offline... If you have made a server via the game, it will only be active / available while you (whomever made that world) is online and in the world... As soon as the "owner" logs off the world logs off.

Multi player, you need to play with people you trust. You can also play solo, and there is no risk there. You can even mix this, and open up your (backed up just in case) solo world to people. Also, if you are controlling the server you play on (you can!) then it can go offline when you stop playing. If you host an always alive server... can't do anything about humans but the NPCS will NOT raid you when you are NOT home.

As far as NPCs go, there are enemy raids on your homestead(s) but there are also plenty of oft repeated tactics here on how to prevent any real damage.
the key points of those include making a moat, raising the terrain (its indestructible to NPC) as a 'wall', taking over a small island to prevent spawns, and so on. Your epic builds CAN be safe but you have to be a little bit proactive to ensure this.

There are wards you can place that keep out players you haven't authorized.

This game its closed co op , so no one can invade your server , if you give your password of course