Is it possible to make a base that's impenetrable by other players?

This question stems from a discussion I had with some friends.

• Consider a hypothetical multiplayer vanilla Minecraft server.
• The landscape is random, not premade or prepared in any way.
• All players are playing in survival mode.
• No cheats are allowed.
• The players don't necessarily want to play as allies (they could form alliances, but there will be opposing sides).
• We want to let the players be completely free - i.e. not have to respect any particular rule (like "don't break blocks in other people's homes"), unless that rule is enforced by the game mode and the environment.

Is it possible for a faction to set up a home base that simply cannot be breached from the outside by other players (unless someone from the inside grants them access)?

Solution 1:

Not reasonably

Nothing you can build in vanilla Minecraft is indestructible.

That said, Simply Sarc recently posted a video on his channel, where he shows off a way to actually make a base indestructible, using 60 Elder Guardians, which are synched up so that one of them uses his curse every second. That means thats any player in the vicinity can't not have Mining Fatigue III for more than a second at a time.

This doesn't make your base truly indestructible, but depending on the material you used for building it, it will make breaking into a base take an awfully long amount of time.

Of course, your team would also be unable to break things inside your base, but you could have a redstone-operated door which can only be opened from the inside.

In pure survival, your team would need to capture these guardians manually, which involves raiding at least 20 ocean monuments. It is also possible to synchronize the curse timers, although the video doesn't go into details, mostly because ot would be utterly ridiculous to even attempt this method of base protection.

Solution 2:

Just make a complete bedrock cube. This is your base. Set your spawn point inside the cube. Make sure there is no entrance. Turn keep inventory on, and when ever you need to get home, just kill yourself. No one can get inside, except you, because their spawn point is not set in your base. They can only get inside through Creative mode. For extra security, make it small, short, and make the floor the bedrock at the bottom of the world. When miners dig down, they'll think your base is the bottom of the world! Or just use command blocks saying only ________ can open base.