A fly system, flying system or theatrical rigging system, is a system of lines (e.g., ropes), blocks (pulleys), counterweights and related devices within a theater that enables a stage crew to quickly, quietly and safely fly (hoist) components such as curtains, lights, scenery, stage effects and, sometimes, people (e.g., in Peter Pan). Systems are typically designed to fly components between clear view of the audience and out of view, into the large opening, fly loft, above the stage.