Anti-Exploit

A set of individually toggleable protections against common survival exploits. Every one is disabled by default and each has its own bypass permission, so staff can be exempted without disabling the feature.

No Slow

Removes the vanilla movement slowdown applied while an item is being used (drawing a bow, blocking with a shield). Implemented with a temporary MOVEMENT_SPEED attribute modifier that is stripped as soon as the player stops using the item, changes held slot, quits, or the feature is disabled.

features:
  no-slow:
    enabled: false
    speed-multiplier: 5.0
    affected-items:
      - BOW
      - CROSSBOW
      - SHIELD
      - TRIDENT

Option	Description
speed-multiplier	Vanilla slows the player to roughly 20% speed, so 5.0 restores normal walking speed. Tune on a live server — armour, effects, and per-item behaviour all shift the real value.
affected-items	Materials that trigger slowdown removal. Unknown material names are skipped with a console warning.

Boat Fly

Detects boats held airborne for a sustained number of ticks and removes the exploit, either by teleporting the boat back to its last grounded location or by ejecting the rider. Water, ice, and any descending movement reset the counter, so normal boating and waterfalls are not flagged.

features:
  boat-fly:
    enabled: false
    airborne-ticks: 20
    action: teleport

Option	Description
airborne-ticks	Consecutive airborne ticks before acting. Too low will false-positive on jumps and waterfalls.
action	teleport returns the boat to its last grounded location, eject removes the rider.

Bypass permission: smp.bypass.boatfly

Anti Elytra

Cancels elytra gliding.

features:
  anti-elytra:
    enabled: false
    mode: combat-only
    worlds:
      - world_the_end

Mode	Behaviour
always	Gliding is never allowed.
worlds	Gliding is blocked only in the listed worlds.
combat-only	Gliding is blocked while the player is combat tagged.

Bypass permission: smp.bypass.antielytra

Anti Totem

Cancels totem of undying resurrections.

features:
  anti-totem:
    enabled: false
    mode: combat-only
    max-per-life: 1

Mode	Behaviour
always	Totems never pop.
combat-only	Totems are blocked while the player is combat tagged.
limit-per-life	Totems pop up to max-per-life times per life, then are blocked until respawn.

Bypass permission: smp.bypass.antitotem

Anti Nether Roof

Keeps players off the nether ceiling, using the world's logical height (normally Y=128).

features:
  anti-nether-roof:
    enabled: false
    action: teleport
    block-placement: true

Option	Description
action	teleport moves the player to safe ground below, damage hurts them instead.
block-placement	Also cancels block placement above the roof.

Creative and spectator players are always exempt. Bypass permission: smp.bypass.netherroof

Anti Overworld Roof

The overworld has no vanilla ceiling exploit, so this enforces a configurable build/travel height limit instead.

features:
  anti-overworld-roof:
    enabled: false
    max-y: 256
    action: teleport
    block-placement: true

Option	Description
max-y	Height at or above which the feature acts.
action	teleport moves the player to safe ground below, damage hurts them instead.
block-placement	Also cancels block placement above the limit.

Creative and spectator players are always exempt. Bypass permission: smp.bypass.overworldroof

Crasher Kick

Cancels oversized payloads used to crash clients, covering written books, creative-mode item transfers, and sign edits.

features:
  crasher-kick:
    enabled: false
    max-payload-bytes: 32000
    kick: true

Option	Description
max-payload-bytes	Maximum allowed payload size before the player is flagged.
kick	true kicks the player, false cancels the action and warns them.

Every flag is logged to console with the offending vector and payload size. Bypass permission: smp.bypass.crasherkick

note

This only covers API-visible payload vectors. Raw packet-level crashers require ProtocolLib, which Vanilla Core does not depend on.

Combat Tagging

The combat-only modes of Anti Elytra and Anti Totem share one combat tag, refreshed whenever a player deals or takes damage from another player (including projectiles).

combat:
  tag-duration-seconds: 15