'Gaming design', advocated by Bill Friedman, focuses on creating smaller, crowded gaming areas with low ceilings and minimal decorations to keep players focused on gambling. 'Playground design', on the other hand, is a newer approach pioneered by Roger Thomas and Steve Wynn with the Bellagio. It emphasizes creating comfortable, luxurious spaces with open rooms, high ceilings, and elaborate decorations to make players feel relaxed and encourage them to stay and gamble longer.