Hitbox

A hitbox is an invisible shape commonly used in video games for real-time collision detection. It is often a rectangle (in 2D games) or cuboid (in 3D) that is attached to and follows a point on a visible object (such as a model or a sprite), though circular or spheroidial shapes are also common. It is common for animated objects to have a set of hitboxes attached to one moving part each to ensure accuracy during motion.