A gallows can take several forms. The simplest form (as often used in the game "Hangman") resembles an inverted "L", with a single upright and a horizontal beam to which the rope noose would be attached. In other designs, the horizontal crossbeam is supported at both ends. The infamous Tyburn gallows was triangular in plan, with three uprights and three crossbeams, allowing up to 24 men and women to be executed simultaneously when all three sides were used.
The apparatus can be permanent, as a deterrent and grim symbol of the power of high justice (the French word for gallows, potence, stems from the Latin word potentia, meaning "power"). Many old prints of British and European cities show such a permanent gallows erected on a prominent hill outside the walls, or more commonly near the castle or other seat of justice. In the modern era the gallows were often installed inside a prison; freestanding on a scaffold in the yard, erected at ground level over a pit, enclosed in a small shed of stone, brick or wood, built into the gallery of a prison wing (with beam in brackets on opposite walls), or in a purpose-built execution suite of rooms within the wing and close to the condemned cell.