Bushnell's Law or Nolan's Law is an aphorism often attributed to Atari founder Nolan Bushnell, on the subject of video game design: All the best games are easy to learn and difficult to master. They should reward the first quarter and the hundredth. This principle is also referred to with the sentence "easy to learn, hard [or almost impossible] to master", which has been adopted by Blizzard Entertainment as a motto and design principle.