Anti-Cheat False Positive Tuning Guide

Why Anticheat False Positive Tuning Matters

Every server running an anti-cheat plugin will eventually punish a legitimate player. Elytra flight triggers fly checks, ender pearl teleports flag speed detections, and high-ping players get flagged for irregular movement. Without proper anticheat false positive tuning minecraft admins end up with frustrated players, flooded appeal channels, and a reputation for unfair moderation. The goal is not to disable checks, it is to raise violation-level (VL) thresholds and exclude known safe actions so real cheaters still get caught while normal gameplay goes uninterrupted.

Understanding Violation Levels

Most modern anti-cheats (Vulcan, Grim, Matrix) use a VL system. Each suspicious action adds points, and once a player crosses a threshold the plugin kicks, bans, or flags them. False positives happen when normal actions accumulate VL faster than the decay timer clears it. The fix is usually one of three things: raise the action threshold, increase VL decay speed, or exempt specific conditions from the check entirely.

Vulcan Example: Flight Check Tuning

Vulcan is one of the most popular anti-cheats on Paper servers. Its default flight check is aggressive, which causes problems with elytra boosting and slime block launches. Open checks.yml and look for the flight section:

# checks.yml (Vulcan)
flight:
  A:
    enabled: true
    max-violations: 25    # default is 15, raise for elytra servers
    decay: 5              # VL removed per second when not flagging
    actions:
      15: "notify"
      25: "kick"

Raising max-violations from 15 to 25 gives legitimate players a buffer. The decay value of 5 means a player who stops triggering the check loses 5 VL per second, so brief false positives vanish quickly. This is the core of anticheat false positive tuning minecraft servers rely on.

Grim Example: Timer and Reach Adjustments

Grim takes a different approach, using prediction-based detection. It still produces false positives, especially on players with 150ms+ ping. Edit punishments.yml:

# punishments.yml (Grim)
Punishments:
  Reach:
    remove-violations-after: 120  # seconds before VL resets
    checks:
      - "Reach"
    commands:
      20: "coc %player% Unfair advantage (Reach)"
      40: "ban %player% 1d Cheating"

Setting remove-violations-after to 120 (instead of the default 60) gives high-ping players more breathing room. You can also raise the command thresholds so that minor VL accumulation triggers a staff notification rather than an instant ban.

Common False Positive Scenarios and Fixes

• Elytra + firework boosting: Triggers fly and speed checks. In Vulcan, set flight.exempt-elytra: true. In Grim, this is handled automatically in newer builds.
• Boat and minecart movement: Vehicle movement confuses speed checks. Grant the permission vulcan.bypass.speed to vehicle riders, or adjust vehicle-specific tolerances in the config.
• Ender pearl teleportation: Triggers teleport and fly checks briefly. Most anti-cheats exempt ender pearls by default, but verify this is enabled in your config.
• High-ping players (200ms+): Nearly every check can false-fire. Increase global max-ping tolerance or set a VL multiplier that scales with latency.
• Creative mode and WorldEdit: Staff using WorldEdit will trigger fly, speed, and packet checks. Grant bypass permissions to your builder rank rather than disabling checks server-wide.

Permission-Based Bypasses

The cleanest way to handle known safe activities is through permissions. In LuckPerms, create a group for activities that legitimately trigger checks:

/lp group builder permission set vulcan.bypass.flight true
/lp group builder permission set vulcan.bypass.speed true
/lp group builder permission set grim.exempt true

This keeps the anti-cheat fully active for regular players while preventing staff and builders from getting kicked during their work. For more on anti-cheat setup and plugin selection, see our anti-cheat setup guide.

Testing Your Tuning

After adjusting thresholds, test with a second account or ask a trusted player to perform the actions that previously caused false positives. Monitor the anti-cheat logs in real time:

/vulcan alerts
/grim alerts

Watch for any remaining flags. If a check still fires on legitimate actions, raise the threshold by another 5 to 10 VL and retest. Anticheat false positive tuning minecraft servers need is an iterative process, not a one-time fix. Game updates, new plugins, and changes to movement mechanics can all shift what counts as "normal" behavior.

Logging and Appeals

Even well-tuned anti-cheats will occasionally flag innocent players. Pair your anti-cheat with CoreProtect logging so staff can verify whether a flagged player actually caused damage. Keep anti-cheat logs for at least 7 days, and create a clear appeal process so punished players have a path to resolution. Use the ban and mute management guide for setting up structured punishment workflows.

Summary

Effective anticheat false positive tuning minecraft servers need comes down to three levers: VL thresholds, decay timers, and permission bypasses. Start with the defaults, identify which checks fire on legitimate actions, and adjust conservatively. Test every change, log everything, and revisit your config after major server updates.

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