What it does
Hold right-click and the vanilla client places a block every four ticks — five blocks a second. FastPlace removes that delay and blocks go down every tick: a wall, a floor or a box around yourself appears in an instant.
In PvP and BedWars that means walling off from an archer in a second, boxing in mid-fight and covering a bed faster than the other team. In anarchy crystal PvP it puts down obsidian for crystals instantly. On survival it's simply unfair building and terraforming speed — a small thing until half the server is doing it.
How to spot it
- A whole row of blocks appears at once, as if pasted rather than built
- Placements tick along like a metronome, faster than players holding the button
- Several blocks pop up at the same moment in different spots in front of the player
How it gets caught
It all comes down to the intervals between placements. Holding the button gives the client a fixed delay, and fast manual clicking is uneven and limited by the finger. FastPlace produces an even stream shorter than that delay, or several placements in a single tick — something neither the button nor a hand can do.
The trap is lag: after a freeze packets arrive in a burst and honest placements look instant. A good check therefore counts how many ticks the client actually lived between placements, not when the packets arrived, and builds evidence over many series, not one wall.