Rules will keep you safe from Dennis. In this fourth-wall--busting story, readers learn immediately that "If you break the rules, Dennis will eat you." The first question is, who is Dennis? Dennis is a large purple monster, not even slightly threatening, with a goofy smile and a "weird thing" on one foot. Enumerated rules commence, ranging from practical ("You must sit on the floor") to silly ("You are now required to moo like a cow") to mindful ("Keep your eyes closed. Feel your heartbeat. Feel the floor"). The six unnamed children shown on almost every page display a variety of skin tones and hairstyles. This fills the bill for teachers or librarians looking for an active storytime choice, though the 11th and final rule ("Feed Dennis…THE BOOK OF RULES") is impossible to carry out, making for a confusing ending. Furthermore, the thread of preachiness throughout, complimenting children on following rules that often align with the behavior adults desire from them, means that some young people will see this as a transparent attempt to get them to follow instructions outside of the story. Still, for groups of kids who want an excuse to make fish faces and give themselves bear hugs, this will occupy several entertaining minutes. (This book was reviewed digitally.) A guidebook that many kids won't mind following. (Picture book. 4-8) Copyright (c) Kirkus Reviews, used with permission.