The world border on a Minecraft server: /worldborder

In short: /worldborder center 0 0 and /worldborder set 20000 put a 20,000 × 20,000 block border around zero — the command sets the diameter, so that's 10,000 blocks in each direction. Since 1.21.9 every dimension has its own border: set the Nether's separately, usually 8 times smaller. Then pregenerate the world inside the border with the Chunky plugin.

The /worldborder command#

The command needs operator level 2; on Paper the permission is minecraft.command.worldborder. It only changes the border of the dimension it runs in; from the console that's the main world.

worldborder center 0 0
worldborder set 20000
worldborder warning distance 10
worldborder get

The Nether and the End: a border each#

In vanilla before 1.21.9 the border was shared by all dimensions; since 1.21.9 each has its own, and the command changes only the current one. So once the Overworld is set, give the Nether and the End their borders through execute in.

Mind the scale: horizontally, one block in the Nether equals eight blocks in the Overworld. So a Nether border 8 times smaller covers the same territory: an Overworld border of 20,000 matches a Nether border of 2,500. According to the Minecraft Wiki, a portal used at the Nether's border won't create an Overworld portal beyond the Overworld border, and travelling through the Nether doesn't take you past the Overworld border.

execute in minecraft:the_nether run worldborder center 0 0
execute in minecraft:the_nether run worldborder set 2500
execute in minecraft:the_end run worldborder set 20000

Growing and shrinking gradually#

With the second argument the border doesn't jump, it moves: a growing border shows green, a shrinking one red. That's how owners widen the world as the player count grows or close in an arena during a PvP event.

• Since 1.21.11 the time is in ticks, with s and d suffixes for seconds and in-game days: worldborder set 30000 600s grows the border over 10 minutes. A number without a suffix is ticks, 20 to a second.
• Before 1.21.11 the time is in seconds: worldborder set 30000 600.
• Since 1.21.11 the border's movement is counted in game ticks rather than real time: if the server falls behind on ticks, the border moves slower too.

What happens at the border#

• Entities can't move through the border. Players outside it, except in Creative and Spectator mode, take damage once they're past the buffer.
• Outside the border, blocks can't be broken, placed or used the normal way.
• Mobs don't spawn naturally outside the border. Since 1.21.2 arrows and tridents bounce off it, and ender pearls and snowballs don't pass through.
• A player can still end up outside: when a shrinking border passes them, after eating chorus fruit near the edge, or when respawning at a spawnpoint beyond it.
• Liquids placed inside flow out through it, and explosions still break blocks beyond it.

Why limit the world#

• Disk space. Every generated chunk is stored on disk and goes into your backups. The border puts a ceiling on the world's size.
• Generation lag. Creating a new chunk costs far more than loading an existing one. Inside a border the world can be pregenerated, and elytra flights stop dragging TPS down — see why the server lags.
• A lived-in world. On a bounded map players meet more often, and the web map and backups cover a finite area.

Pregenerating inside the border#

The Chunky plugin can take its area straight from the border: chunky worldborder uses the border's center and radius for the selected world. The full procedure and tips on hardware and disk space are in pregenerating the world.

chunky world world
chunky worldborder
chunky start

chunky world world_nether
chunky worldborder
chunky start

The vanilla border is always square. For a round world there's the ChunkyBorder add-on (GPL-3.0, runs on Paper): it creates a border from a Chunky selection of any shape, keeps players from going past it, redirects teleports that land outside, and can optionally wrap the border.

The border and the anticheat#

A border answers where the world ends, not how fast players get to the edge. Movement cheats — ElytraFly, BoatFly, Fly, Speed and Timer — cross the map faster than any honest player: the server has to load and generate chunks faster than it's built for, and distant bases get found in minutes. DGuard — the best anticheat for a modern Minecraft server — checks all of them and gathers evidence instead of rushing to a verdict, so an honest player's lag spike doesn't turn into a ban.

FAQ#