What causes a GameMaker character drifting while the gamepad stick is idle?

You read gamepad_axis_value directly and feed it into movement without a deadzone, so the controller's small resting noise registers as continuous low-magnitude input.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix GameMaker Character Drifting While the Stick Is Idle

Quick answer: Apply a deadzone with gamepad_set_axis_deadzone, or clamp small magnitudes to zero in code before using the axis for movement.

If your hero slowly slides across the room while the stick is untouched, the analog noise is leaking into movement. Adding a deadzone fixes it. Here is how.

How to fix it

1. Set a per-device deadzone

Call gamepad_set_axis_deadzone(device, 0.2) in a controller-setup script. GameMaker then zeroes any axis reading below that magnitude automatically.

2. Clamp in code as a backup

Read both axes, compute the vector length, and if it is under your threshold set movement to zero. A radial check handles diagonal drift better than per-axis clamping.

3. Re-apply on reconnect

The deadzone is per slot, so re-run the setup script when async_load reports a gamepad reconnect or the value resets to the default on the new device.

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 GameMaker 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.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.