How to Fix Players Speed-Hacking Through Client-Authoritative Movement

If clients tell the server where they are, a cheater simply lies. The fix is to never trust client positions and instead validate movement on the server against physically possible bounds.

How to fix it

1. Send inputs, simulate on the server

Have clients send input commands and let the server run the movement simulation, so the authoritative position is computed server-side and cannot be forged.

2. Validate the per-tick delta

If you keep client position for responsiveness, reject any update where the distance moved exceeds maxSpeed * elapsedTime plus a small tolerance, snapping the player back to the last valid spot.

3. Rate-limit and log anomalies

Flag clients that repeatedly produce out-of-bounds movement for review rather than only correcting silently, so persistent cheaters can be actioned.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.