FlexBorder

FlexBorder replaces the usual square world border with a rectangular safe zone whose X and Z size can be set separately. The default border covers a 2000×2000 area. Each shrinking stage is generated ahead of time, so the zone contracts gradually and the following zone already exists inside the current one before its phase starts. The border nudges players softly toward the safe zone when they drift just outside it, and a rescue teleport moves anyone who gets too far outside, with brief fall-damage protection afterwards.

The mod can run an entire match from one command. Eligible players in the current dimension are registered automatically, and each receives a clickable READY button in chat rather than typing a command. When every participant has confirmed, a full-screen countdown opens and each player is moved to a random safe spot within the boundary. A configurable development phase comes first, where a max-health penalty on death works like Mediumcore, and when it ends Hardcore mode begins. Solo matches are supported, so the full system can be tested with one player.

FlexBorder is published for NeoForge only, for 1.21.1 – 1.21.11, under All rights reserved and not open source. Every player and the server need a copy of the mod.