AntiLavaCast

Prevents high altitude lava placement to stop lava casting on Paper 1.21.x.

Features

• Cancels lava bucket placement, flow or both if it is more than the configured height above natural ground.
• Uses CoreProtect history (when available) to identify player-placed blocks for accurate ground detection.
• Logs a server alert when a placement is blocked.
• Supports live config reload and runtime toggling.
• Lava casting attribution, optional logs will tell you who tried to place lava and where.
• Maintains natural world lava flow.

[AntiLavaCast] Blocked lava placement by CevAPI at -85,164,-29 (heightAboveGround=96, groundY=68)

Requirements

• Paper 1.21.x
• Java 21+

Install

1. Download the jar.
2. Drop the jar into your server plugins folder.
3. Start the server to generate the config.

Commands

• /lavacast reload
• /lavacast enable
• /lavacast disable
• /lavacast setheight <blocks>
• /lavacast drop <on|off> on allows dropping
• /lavacast flow <on|off> on allows flowing
• /lavacast logs <on|off> on logs blocked placements
• /lavacast coreprotect <on|off> toggles CoreProtect integration
• /lavacast coreprotectlookback <seconds|1m|2h|7d|4w> sets how far back CoreProtect history is searched
• /lavacast mark <radius> marks nearby blocks as player-placed for height checks (max radius 100)

Permissions

lavacast.admin (default: op)

Config

plugins/AntiLavaCast/config.yml

max-height-above-ground: 20
enabled: true
allow-lava-drop: false
allow-lava-flow: false
log-blocked-placements: true
coreprotect-enabled: true
coreprotect-lookback-seconds: 31536000

Notes

• The ground scan ignores player-placed blocks; when CoreProtect is available it will also treat historical placements as player-placed.
• Use /lavacast mark <radius> around old builds to mark them as player-placed if CoreProtect is not available.
• Marked blocks are stored on disk in plugins/AntiLavaCast/marks and persist across restarts.
• When CoreProtect is enabled and detected, mark storage is disabled and lookups rely on CoreProtect instead.