In plain language
Shake/tilt/motion features need a normal on-screen control and an off switch.
Who it affects
People with tremor and people whose device cannot be moved freely.
How to check
Identify motion-triggered features: verify a button alternative and a setting to disable motion input. Worked example — A nonprofit's donation form: try to pass an onboarding step via a button instead of a device-orientation gesture: if there's no alternative and no way to disable the requirement, it fails.
Common misconception
This rule isn't just about games. Any feature that responds to shaking or tilting, including “shake to undo” in a mainstream app, needs a settings toggle to turn it off. Real example: on a streaming music app's search results, a shake/tilt-controlled feature can't be switched off — users with tremors trigger it accidentally, and users who can't move the device can't use it.