What it does
Eating, drinking a potion, drawing a bow or raising a shield normally slows a player to about a fifth of their speed. NoSlow removes that: a golden apple gets eaten on the run, potions go down without breaking stride, and a shield doesn't cost any pace. Many versions also ignore cobwebs, soul sand and honey.
In PvP it decides fights: the cheater heals without giving up distance and shoots a bow at full speed. When fleeing, they pull away while regenerating, and a cobweb trap doesn't hold them.
How to spot it
- Eats or drinks (particles at the mouth, the sound) while moving at sprint speed
- Draws a bow or loads a crossbow without slowing down
- Keeps pace with sprinting players while holding a shield up
- Walks through cobwebs, or soul sand without Soul Speed, at normal speed
How it gets caught
Starting and releasing an item use arrive as separate packets, so the server knows exactly when the player was eating or blocking. For that window the anticheat builds slowed movement into its prediction and compares it with what the client sent. Running speed mid-meal contradicts the physics outright.
Latency blurs the edges of that window: the player may have already let go while the packet is still on its way; switching hotbar slots mid-meal, knockback, ice and a Speed effect also change the picture. So a single overshoot is written off as desync, and evidence comes from repetition.