Jenga is played with 54 wooden blocks. Each block is three times as long as it is wide, and one fifth as thick as its length – . Blocks have small, random variations from these dimensions so as to create imperfections in the stacking process and make the game more challenging. To set up the game, the included loading tray is used to stack the initial tower which has eighteen levels of three blocks placed adjacent to one another along their long side and at right angles to the previous level (so, for example, if the blocks in the first level lie lengthwise north–south, the second-level blocks will lie east–west).