A Jacob's ladder (also magic tablets, Chinese blocks, and klick-klack toy) is a folk toy consisting of blocks of wood held together by strings or ribbons. It is "a toy that does some very weird things." When the ladder is held at one end, blocks appear to cascade down the strings. This effect is a visual illusion which is the result of one block after another flipping over. It may be considered a kinetic illusion, where the blocks appear to change position when they do not.