It’s wise to step sidewise now and then. We mostly navigate the complexities of our lives in plan A ways. Both everyday experience and research show how simple habits and rules of thumb help us make decisions, exercise willpower, learn novel ideas, and pursue personal and broader innovations. Ninety percent of the time, that works out okay. But what about the other ten percent? For trickier situations, a sidewise mindset helps. People often override their usual rules with “unruly rules,” rewriting ordinary habits and expectations for more effectiveness and imagination. SIDEWISE explores this world of unruly rules and what it offers. We look at the routines and conventions that commonly govern, map cognitive mechanisms that sometimes create blind spots, and reveal mental butterfly effects that help us pivot in seconds onto smarter paths.