Detect and fight the exploitation of various flaws/bugs in Minecraft!

Features Permissions Commands Configuration Jenkins


NoCheatPlus attempts to prevent cheat clients from exploiting weaknesses of Minecraft or its protocol, making your server more safe. Checks cover a wide range of issues including flying and speeding, fighting hacks, fast block breaking and nukers, inventory hacks, chat spam and other types of malicious behaviour. For a more complete list have a look at the Features Page.

NoCheatPlus puts emphasis on configurability and allows you to customize actions that are carried out when a player fails a check (e.g. silent cancelling, executing commands, just logging). Bypass permissions allow to control what check to apply for which players, all checks can be deactivated in the configuration, also having the option for world-specific configuration files. Many checks allow more detailed configuration to adjust sensitivity.

Certainly NoCheatPlus is not a magical bullet, it uses a lot of heuristics and even guessing, so you will encounter false positives here and there and also not catch every single violation. Example video of how NoCheatPlus blocks cheats (outdated plugin version).

NoCheatPlus was introduced by NeatMonster, building on the code base of NoCheat by Evenprime.

The following plugins might be useful to have a look at.

CompatNoCheatPlus (cncp)

Make plugins like mcMMO, Citizens, MagicSpells or MachinaCraft more compatbile with NoCheatPlus. Not all existing plugins are covered (yet), but you can leave a note or ticket request for cncp.


Orebfuscator fights all sorts of X-ray-hacks by altering the map information that is sent to the players, such that they have to mine blocks to actually reveal what is behind. Virtually a "must have".

Downloads and History of Changes

  • Download officially approved versions on the Files page at BukkitDev.
  • Development builds have been moved over to the Jenkins at EcoCityCraft.
  • Do not download from any other source, do not use jars other people send you.
  • Changes by build number can be examined in the Jenkins changes list.
  • All commits can be seen in the GitHub commit history.
  • Plugin statistics are no longer reported to


Documentation Resources

Contact us

  • Quick questions can be asked on this page,
    or on IRC (Server: | Default-Port: 6667 | SSL-Port: 6697 | Channel: #nocheat | Web client: WebIRC)
  • For real issues or feature requests please create a new ticket or add to an existing ticket.
  • To send information that is not to be seen by all, you can also reach us by PM to @asofold and @MyPictures. Please do not contact the user 'NoCheatPlus', it is for administrative purposes only and will likely not be answered in time. Keep to BukkitDev and GitHub for support, do not trust users on other forums or websites, also not if their nick names are the same as NCP staff on BukkitDev.

Please always state the output of the "ncp version" command to let us know versions in use (users of cncp also the "cncp" command).

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  • Avatar of asofold asofold Nov 12, 2012 at 00:04 UTC - 0 likes

    @andrewkm: Go

    @Demonlover11: Go

    Looks like Minecraft / authentication stuff. If you restart client it should work, sometimes trying to relog works.

    Especially when i connect to a local server which then runs in in online-mode=false and the connect to a server in online-mode i will get that error consistently. So i assume it is Minecraft authent.


    Latest beta release (+ 1.8.3, approved) NoCheatPlus 3.12.0-RC-sASO-b813
    (Development builds, 1.8: Jenkins)

  • Avatar of Demonlover11 Demonlover11 Nov 11, 2012 at 23:54 UTC - 0 likes
    @andrewkm I also get the same error with my server and it's a constant 25 ~ 40 player server. @MyPictures Will do.

    Website: <- MC Server + More!

  • Avatar of andrewkm andrewkm Nov 11, 2012 at 23:28 UTC - 0 likes

    Im pretty sure this is NoCheatPlus preventing too many logins at once; after a server restart a TON of people are getting Failed to login: Error

    It works after a while however. I am running build #239 My configuration is absolutely default.

    I remember once asking asofold to make the too many logins check delay itself after server start for massive servers who run auto restarts. Asofold added it and all was perfectly fine. However just recently for some reason this Failed to login: Error has been hitting us during too many logins. Any ideas what is going on and why this is happening? Perhaps an issue with NCP's delay?

    We run a 200/200 user server; and after auto restart our player slots filling back up time quite some time now.

    Seems to happen on other servers too. Hmm perhaps a Mojang session servers issue? The other servers do as well have NCP, now im confused.

    Last edited Nov 11, 2012 by andrewkm
  • Avatar of MyPictures MyPictures Nov 11, 2012 at 23:15 UTC - 0 likes

    @Demonlover11: Go

    For mcmmo you can just use CompatNoCheatPlus with NoCheatPlus:

    I check that snow one now, it would be very nice if you could make a ticket about this issue for us with more info's.


  • Avatar of Demonlover11 Demonlover11 Nov 11, 2012 at 22:44 UTC - 0 likes
    What would I change or disable to allow Tree Faller from McMMO to not kick a user? Also, when a user walks in snow they get knocked back for flying, how do I make it where it only notifies me something a user is doing and does not cancel their action?
    Last edited Nov 11, 2012 by Demonlover11
  • Avatar of asofold asofold Nov 11, 2012 at 19:31 UTC - 0 likes

    @OctyArThMc: Go

    Please use a paste or such logs and also rather create a ticket. Also paste the full exception trace and if possible include something of what happened afterwards.

    A plugin list might be interesting too (pm or in ticket.).

    Mind the latest development builds to be found at:

  • Avatar of OctyArThMc OctyArThMc Nov 11, 2012 at 19:12 UTC - 0 likes

    I use the last version 3.8.0 with CraftBukkit version git-Bukkit-1.4.2-R0.2-b2455jnks.

    I have a big error, afther the message from nocheatplus my server crashed, can evryone help me?

    19:55:49 [INFO] laureuu -> paicu: si tre sa ard blocku? 19:55:49 [INFO] [G] [Moderator] Griefer Ionut1: gata e ascuns! Indiciu : e dur acolo dati ./warp orasulapelor si cautati 19:55:49 [INFO] centurion -> kevinutu00: ok 19:55:49 [INFO] paicu -> laureuu: damil 19:55:49 [INFO] [NoCheatPlus] mha failed FastBreak: tried to break blocks (1) faster than possible. VL 0. 19:55:49 [INFO] [NoCheatPlus] Enginer failed FastBreak: tried to break blocks (18) faster than possible. VL 0. 19:55:49 [INFO] [NoCheatPlus] DJ_ANDY failed FastBreak: tried to break blocks (1) faster than possible. VL 1. 19:55:49 [INFO] [NoCheatPlus] grasunel failed FastBreak: tried to break blocks (5) faster than possible. VL 4. 19:55:50 [INFO] vladro1 issued server command: /tpaccept 19:55:53 [INFO] Connection reset 19:56:16 [INFO] Connection reset 19:56:28 [INFO] Connection reset 19:56:34 [INFO] Connection reset 19:56:35 [INFO] Connection reset 19:56:37 [INFO] Connection reset 2012-11-11 20:03:59 [SEVERE] null Input/output error at Method) at at at at at org.bukkit.craftbukkit.libs.jline.console.ConsoleReader$ at at at org.bukkit.craftbukkit.libs.jline.console.ConsoleReader.readCharacter( at org.bukkit.craftbukkit.libs.jline.console.ConsoleReader.readLine( at

  • Avatar of asofold asofold Nov 11, 2012 at 10:32 UTC - 0 likes

    @mrchasez: Go

    If you have severe lag spikes you should adapt the configuration to not get spammed too much.

    And to be plain - NCP certainly does not assume the world to be ending, it just prevents some actions of the players, because NCP can't really distinguish cheating from effects of lags in some cases. Some cases might be fixable for the case of server lag, some certainly are not fixable in a way that still prevents cheating.

    I assume it might be seconds-range lag spikes rather than "dropping to 14 or 17 tps", so you should disable the ingame logging for lower vls for the checks that are most influenced by lag. Also take a look at the configuration page (fastbreak) increase the (yet hidden) contention setting to match lag better.

    The topic of lag + skipping checks or notifications is still on the list, though.

  • Avatar of mrchasez mrchasez Nov 11, 2012 at 09:33 UTC - 0 likes

    @asofold: Go

    Already using build 3.8.0 The issue with NoCheatPlus is that it assumes the server is running 20TPS and never has lag spikes. The second a lag spike happens the plugin thinks the world is ending by how much spam we get. Every three seconds we get messages like "Name meets the improbable more then expected" when they are simply building there home.

    We get false fastbreak notifications all the time. Oh "name tried to do "blank" with too high a frequency" happens a lot aswell.

    The thing is. with us and most servers, our TPS dips to 14/17 sometimes, We have nearly a hundred players online, we get lag spikes once in a while.

  • Avatar of asofold asofold Nov 11, 2012 at 07:59 UTC - 0 likes

    @mrchasez: Go

    I think it is an issue with CB/MC rather, because the check is pretty accurate and harmless.

    Please update NCP as well. False positives are very unlikely with relog, what might have happened is a severe server problem disconnecting the players without assuming them disconnected, on relog they will instantly logout and login (from the perspective of the server), so ncp prevents that. It is more likely to be a server crash problem (see pm).


Date created
Apr 02, 2012
Last update
Mar 21, 2015
Development stage
GNU General Public License version 3 (GPLv3)
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