Why does a phone that slips out of your hand so often land screen-down?

Answer: It is usually tilted when it slips, and a hand-height fall gives it about half a turn before impact

Bad luck singles out the expensive side — Wrong. It feels like a law of nature, but no outcome is guaranteed. The landing depends on the tilt at the moment of the slip, the drop height and the shape of the case; change any of them and the phone lands on an edge or screen-up just as happily. The real pattern is probability, not spite.

It is usually tilted when it slips, and a hand-height fall gives it about half a turn before impact ✓ — Correct! A phone is usually held screen-up and slightly tilted, so when it slips, gravity starts it rotating around the fingers that last touched it. From a typical hand height of about a metre there is often time for roughly half a turn before impact, which is why screen-down is more common than you would expect, though far from guaranteed. Grip, angle, height and the case all change the outcome, and the same physics is behind toast landing butter-side down.

Air resistance flips the screen toward the floor — Wrong. Air resistance barely affects a dense, flat phone over a one-metre fall. The rotation that turns the screen downward comes from the tilt and spin the phone already has when it leaves your hand, not from air pushing it over.