Playfield Shakers

A playfield shaker is a player-operated control that jolts or shifts the Playfields to influence a ball already in play.

It’s a rare mechanism, existing only on a handful of machines. And the shakes are often rationed: Bally’s Hi-Fi (1954) puts buttons where the flipper buttons would be and “allows the player to ‘bump’ the playfield up to ten times per game”,^[1] while Sega’s Skill Ball (スキルボール) jolts “the playfield forward about an inch”^[2] a number of times bought with the tokens that started the game.

The tilt circuit

Playfield shakers often interact with the tilt circuit. Hi-Fi suppresses the tilt so the bump is safe — “There is a delay feature on the tilt circuit to prevent tilting during a ‘bump’.”^[3] Allied Leisure’s Sea Hunt (1972) and Spooksville (1973) leave it armed, so the shake carries risk: “Pushing too sharply will tilt the ball in play.”^[4] That tension is what the mechanism is: the sanctioned form of a thing every other machine punishes.

Not a shaker motor

Shaker Motors are activated by the game itself, shaking during specific gameplay moments,^[5] whereas playfield shakers are player-controlled.

Not a tilting playfield

Tilting Playfields are playfields that the player holds at an angle to aim to ball, whereas playfield shakers deliver a jolt or thump.