Pie menu

A pie menu is a user interface which is designed for quick selection of a limited number of options in a computer application, usually with a mouse. A typical pie menu requires the user to click a mouse button within a certain screen area, after which the pie menu "pops up". Several "pie slices" are displayed around the center, each with an individual label (e.g. "Open", "Close" at the top and bottom, "Next", "Previous" at the left and right). The user then moves the mouse, often while still holding the mouse button, into the desired slice. After doing so, he either has to release the mouse button, or select the respective option by clicking it.

Pie menus are often used in games (examples: The Sims, Monkey Island 3, Full Throttle, Neverwinter Nights) because they only require screen space when activated. As opposed to context menus, they allow very fast access to commonly used actions, as the experienced user is able to immediately execute a certain action by simply moving the mouse in the appropriate direction while pushing the button, and then releasing it. This is similar to the way mouse gestures work, but differs in that the user does not have to consult a manual or rely on trial and error before being able to use the gestures. For applications which are used regularly, mouse gestures may be preferable because of their lower intrusiveness. Optionally, pie menus may be designed in such a fashion that they only pop up when the mouse button has been held down for a certain amount of time, so they operate like mouse gestures when used quickly.

Example for a pie menu taken from the computer game The Sims. The player can choose the options by moving his mouse away from the center into one slice of the "pie".