Minecraft anticheat guide
Why Combat Anticheats Need Occlusion
Why attacks through blocks, target visibility, and block-shape evidence matter for Minecraft PvP fairness — independent of any single anticheat.
The client sees a hit; the server must verify the path
A combat client renders the world from its own viewpoint and reports an attack it believes connected. The server owns the authoritative question: was there a plausible, unblocked path between attacker eye position and the target's collision shape at packet time? Raw attacker-to-target distance cannot answer that on its own.
Occlusion is the missing half of reach. A hit inside raw range but behind solid geometry is a different allegation than a long hit across open air, and staff need the anticheat to separate the two instead of merging them into one distance number.
Server collision shapes differ from what the eye sees
What looks open on a client screen may be covered by server-side collision shapes: full blocks, partial blocks, and shapes the attack ray must be tested against. Visibility checks ask whether those shapes plausibly block the ray, using cached world and block state from the correct tick rather than a live read from the wrong thread or a stale snapshot.
This is why occlusion belongs beside hitbox validation rather than inside a yaw, pitch, or broad field-of-view filter. Direction alone says where the attacker looked; occlusion says whether anything solid stood in between.
What to demand from an occlusion claim
Ask for the recorded evidence per flag: measured eye-to-hitbox distance, the target box used, the ray result, the occlusion verdict, and the ping and transaction context around the attack. FairPlay's HitboxOcclusion and HitboxBlockOcclusion checks sit in that family; any Plugin Developer’s equivalent should expose the same variables before staff treat a flag as proof.
Keep occlusion alert-only until production data shows which geometries are clean on the exact server build. Block-heavy arenas, custom blocks, and high-latency profiles all shift what plausible looks like.
FAQ
Is occlusion just long-reach detection?
No. Reach measures distance plausibility; occlusion measures path plausibility through server-side block geometry. A hit can fail either independently.
Can a client-side recording settle an occlusion dispute?
Not alone. The attacker's screen shows visible client state, while the verdict needs server collision shapes and packet-time positions.