There are plenty of shapes out there and all of them are just fine. There is no big difference in the shape, as long as it is created with caution. Two of the most common shapes were mentioned in Chapter 1, Introduction to Quadcopters. Apart from the X and plus shapes, there is an H frame and other more complicated ones. Generally, most hobbyists choose the frame shape according to what they believe will be more beautiful and elegant. Furthermore, there are some techniques and shapes that are suitable for fast quadcopters, in case you need as much acceleration as you can get. There are not many races out there but, in the future, races using quadcopters are going to be very common and everyone will try to get as much acceleration as they can. Note that the discussion in this section of the chapter will be about shapes and not sizes.