QMBorderGuard

World borders made of a polygon you walk out yourself. Place at least three nodes around an area and the region becomes active: players get stopped at the edge with a puff of smoke, and staff who turned the preview on see the whole outline drawn in particles. Regions are per world, so the nether and the end can have completely different shapes.

No dependencies. Paper / Spigot 1.12.2, Java 8.

Quick start

/border wand

Action	Effect
right click	add a node at your feet
left click	remove the last node
sneak + right click	toggle the border preview

Walk around the area you want to enclose, clockwise or counter-clockwise, and the region switches on once the third node is placed. Concave shapes work: the polygon is the node order, so do not zigzag back across yourself.

Without the wand: /border add and /border undo.

Commands

Command	Does
/border help	list everything
/border add / undo	node at your feet, undo the last one
/border remove <n>	delete node n, counting from 1
/border insert <n>	insert the node at your feet as node n
/border list [world]	nodes with their coordinates
/border clear	drop every node of this world
/border tp <n>	teleport to a node
/border on / off	enable or disable the border of this world
/border min <n>	nodes required before the region activates
/border y <low> <high>	only intercept inside this height range
/border y full	no height limit (default)
/border spawn	set the rescue point at your feet
/border toggle	your own preview, on or off
/border bypass	ignore the border yourself, for building
/border info [world]	node count, y range, rescue mode
/border reload	reload config, messages and region files

Aliases: /bg, /boundary, /bianjie, /边界.

Permissions: borderguard.admin (op), borderguard.bypass (nobody by default).

Files

plugins/BorderGuard/
├── config.yml            settings, wand, rendering, effects
├── messages.yml          every message, with {0} {1} placeholders
├── debug.yml             who has the preview on, maintained by the plugin
└── regions/
    ├── world.yml
    ├── world_nether.yml
    └── world_the_end.yml

Each region file holds the node list, the y range and whether the border is enabled. Nodes are stored as plain coordinates rather than world references, so a world that is not loaded never loses its data.

How the interception works

settings.rescue decides what happens to a player who is already outside:

• PUSH pulls them back towards the nearest inside point, rescue-speed blocks per tick. 0.9 holds up against a sprint.
• SPAWN teleports them to the rescue point set with /border spawn.
• NONE only blocks crossings from inside to outside, which is useful when the border is decorative.

Movement is handled per axis, so a player running into the border slides along it instead of stopping dead. Ender pearls and similar teleports are checked as well (teleport-guard), and players who log in outside the region are sent back (rescue-on-join).

Creative flight and spectators are not exempt by default; settings.ignore-gamemodes is where to add them, and ignore-ops decides whether operators are stopped too. Turning that on is handy while building, which is what /border bypass is for.

Rendering

The line is only sent to players with the preview on, refreshed every render.interval-ticks and only within render.radius blocks. render.step is the distance between particles, so lowering it thickens the line at the cost of packets. Node markers are drawn as pillars of node-pillar blocks.

Effects on touch live under effects: a list of particle groups with count, offset and speed, plus a sound. Nothing there is hardcoded, so replacing the smoke with flame or portal particles is a config edit.

Build

mkdir -p lib   # spigot-api.jar (the patched 1.12.2 server jar works too)
bash build.sh
# or: MC_SERVER=/path/to/server bash build.sh install

Output: build/BorderGuard.jar.