NoCheatMinus

This is a recode/port of an "Commandblock"-AntiCheat in Vanilla Minecraft, that existed back in 2016, as a Datapack for Minecraft 1.21+. Its purpose is the detection of generic game modifications by checking and tracking movement, fight and network behavior of players constantly, followed by a configurable comparison of the collected data with the expected behavior.

• Visit the NoCheatMinus Test Server: test.nocheatminus.org
• You can view an (outdated) demonstration here.
• If you have questions, suggestions, or feedback, join our Discord server here.

Setup

0. First, you need to install the latest version of VanillaEvents in your world. VanillaEvents is installed in the same way as NoCheatMinus and can be downloaded here.
1. Download the NoCheatMinus project as a .zip file, un-zip it and place the folder (which contains the "data"-folder) in your world's datapack folder.
2. Restart your server or use /reload to reload the datapacks.
3. Use the command /scoreboard players set @s ncmOperator 1 to obtain operator rights in NoCheatMinus, which will allow you to execute commands that start with /trigger ncm....

Apply values from configuration files

1. Paste your configuration files into the directory NoCheatMinus/data/ncm/functions/user/configs/
2. Edit the file NoCheatMinus/data/ncm/functions/user/currentconfig.mcfunction/ and assign a configuration file to each configuration slot.
3. Run the command /scoreboard players set DataHolder ncmCC <slot> to specify the slot in which the desired configuration file is located.
4. Restart your server or use /reload to reload the datapacks.

Update to a newer version of this Datapack

1. Replace the outdated directory "data" with the updated one.
2. Restart your server or use /reload to reload the datapacks.

Checks

Check category and name	Description
BlockPlace.Appropriate	NCM monitors the amount of blocks placed in a configurable time window.
BlockInteract.MissingBlock	When the player interacts with a block, NCM will check if the player looks at a block, which blocktype equals the blocktype of the block he interacted with last, and if this block is within the max interaction range. (Raytracing).
Net.UnfittingPacket	NCM checks if the player spoofs to be on-ground whilst being mid-air/off-ground. Another subcheck of this check monitors if the player sends a RespawnPacket whilst being alive or stops receiving certain packets without being dead (Godmode patch).
Net.Appropriate	NCM checks if the DeathTime-NBT-Data of the player is appropriate (GodMode patch) and if the player respawns too fast (InstantRespawn).
Movement.TickStride	NCM evaluates player movement events based on distance and logs or cancels events if the configured thresholds are exceeded, aiming to maintain gameplay integrity and prevent unintended movement exploits.
Movement.SurvivalFly	NCM monitors the vertical motion of the player, the off-ground-behavior, unexpected movements, the player's gravity, and lost-ground-situations.
Movement.NoFall	When the player touches the ground, NCM will start calculating the estimated fall damage, depending on the current health and the fall distance. If the taken fall damage differs from the calculated fall damage, this check fails.
Fight.Criticals	When a player makes a critical hit, this check verifies that the hit was made under legitimate conditions.
Fight.Reach	NCM checks if the player has hit an entity that is out of his legitimate range.
Fight.WrongTurn	NCM monitors the players pitch-turns.
Fight.CompliantVelocity	This check monitors the movement reaction of the player after being hit.
Combined.BedLeave	NCM checks if the player sends BedLeave packets without being in a bed first. The small teleport after leaving a bed can be used by players with a cheat client for flying or speeding.
Combined.Munchhausen	According to the legend of Baron Munchausen's tall tales, players can pull themselves out of the swamp by their own hair. NCM checks if cheat-clients use this ability for flying/speeding.
Inventory.Appropriate	When the player consumes an Item, NCM will check the speed of consuming and compare it with the configurated appropriate values.
Inventory.InstantBow	This check monitors the player's arrow-shooting speed.