tiltingapinballmachine

Before video games, people would play pinball in arcades, where a steel ball is physically controlled through a slanted playing field by mechanical flippers, bumpers, etc. Sometimes it was necessary to bump or tilt the machine one way or another to prevent losing the ball. To limit this activity and prevent damage to the machines, manufacturers installed a tilt sensor – if the machine was tilted too far or bumped too hard, the current ball was declared invalid and lost.

So, the good players learned how to tilt without being caught by the tilt sensor, and would get to know how the tilt mechanisms in different machines behaved.