Why Anti-Cheat Matters
Cheaters ruin the experience for legitimate players. Killaura, speed hacks, X-ray, and fly hacks are common on public servers. A good anti-cheat catches these automatically.
Grim Anti-Cheat
Grim is the most accurate free anti-cheat available for Paper servers. It simulates server-side physics to detect impossible player movements. Best for competitive or PvP servers. Open source and actively maintained.
Vulcan
Vulcan is a premium anti-cheat with excellent detection rates and a helpful developer. Good for servers that want a well-rounded paid solution with support.
Matrix
Matrix is a popular paid option with cloud-based detection. Easy to configure and good for general-purpose servers.
NoCheatPlus (NCP)
NCP is the classic free option, around for over a decade. Detection accuracy has fallen behind compared to modern alternatives but it works fine for casual servers.
Recommendation
For competitive servers: Grim (free) or Vulcan (paid). For casual survival SMPs: NoCheatPlus or even just CoreProtect for rollbacks is enough. Heavy anti-cheat is not always necessary on whitelisted private servers.