Themis Anti Cheat | 1.17 - 1.21 | Bedrock Support | Paper Compatibility | Free, Optimized

This plugin only works on Minecraft versions 1.17.0 - 1.21.10!

For Bedrock support you need to install the Bukkit/Spigot version of Floodgate (both 1.0 and 2.0 are supported)!

If there are any issues, instead of leaving a bad review please join the Discord so that we can help you!





Themis is an anti cheat with a focus on accuracy, efficiency and simplicity.

I highly recommend joining the Discord server to stay up to date and get support.

Themis supports Spigot and Paper. Other forks will probably work too, but I can't guarantee it.

Also Themis has real Bedrock/Geyser support! By "real" I mean that it actually performs proper checks on Bedrock players. Some other anti cheats simply exclude Bedrock players from the checks, which means that they can fully bypass the anti cheat. With Themis this is not the case!

Note that supporting Bedrock is more difficult than Java since it's a completely different codebase and Geyser has bugs that cause random weird behaviour (Geyser is an absolutely amazing piece of software though!), so there will be false positives. Please report them on Discord to help me fix them!

Themis has a flexible config that allows you to configure an arbitrary number of actions that can consist of an arbitrary number of commands which should be run. For each action you can define a minimum score required to run, and a score and time delay for it to be run again. All of this can be configured for each check individually. You can find the config in the config section below.

Themis currently focuses on movement hacks but will expand and detect more hacks in the future.

The plugin Anti Cheat Replay supports Themis and can be used to record players when getting punished by Themis so that the recordings can be reviewed and used as evidence later.

• BHop Speed
• Blink
• Boat Fly
• Boat Speed
  
• Climb / Spider
• Elytra Fly
  
• Fly
• Jetpack
• KillAura if it uses increased Reach
  
• NoFall
• OnGround Speed
• Reach
  
• Step
• Timer
• Vanilla Speed
• WaterWalk / Jesus

Note that this list is not complete. Some checks can catch hacks they weren't even designed for, and some hacks can have many different names in different hack clients, so even if a hack is not on this list, there's a chance it's blocked anyways, especially if it's similar to the ones listed.





Themis doesn't just promise efficiency, it also delivers it. This is a timings report over an hour of a server running Themis 0.8.1 with all checks enabled and about 15 players online.

It shows that on average Themis uses 0.23% of the tick, which is about 0.015% per player. Of course this number will vary, depending on your server hardware and setup (plugins, gamemodes, ...).

For comparison, as of writing this (13th April 2021), AAC has a similar statistic on its plugin page where it uses 3.92% for 140-150 players which is about 0.026% to 0.028% per player, so Themis is almost twice as fast.

(Note that this is not at all a fair comparison since AAC has a lot more features than Themis! I didn't put this here to say Themis is better, I just think the statistic alone will be meaningless to most people, so I wanted some reference point, and I chose AAC because it's a well optimized anti cheat, it's widely known and it has a similar statistic on its plugin page.)

If you notice any mistakes in these calculations please let me know!





To install Themis, please carefully follow these steps:

• Make sure you're running version 1.17.X, 1.18.X or 1.19.X, 1.20.X or 1.21.X of Spigot or Paper. Other forks will probably work too, but I don't guarantee it.
• Download the Themis .jar file from this page and drop it in your plugins directory. (You don't need ProtocolLib anymore, starting with version 0.17.0)