Drawing on more than a decade of rigorous research, Sull and Eisenhardt provide a clear framework for developing effective rules and making them better over time. They find insights in unexpected places, from the way Tina Fey codified her experience working at Saturday Night Live into rules for producing 30 Rock (rule five: never tell a crazy person he’s crazy), to Japanese engineers using the foraging rules of slime molds to optimize Tokyo’s rail system. This is the definitive playbook for living simply and efficiently in every sphere of life