Rotation is the circular movement of an object around a specific axis.
One of the primary forms of movement transformation on an object in space, alongside translation and reflection.
In games, especially 2D games, rotation can provide a lot of complexity in comparison to translation and reflection. For example, in collision detection, rotation does not guarantee the same borders and hitbox that are preserved in the other methods. Questions under the purview of this tag include all manner of scenarios dealing with the consequences of rotating an object in space.
Not to be confused with other definitions of rotation, such as "rotating through a roster of units".