This book is solely responsible for helping to create the single most successful DnD 5e campaign that I have ever run. My roommate and I were inspired by Matt Colville's video on West Marches-style play (https://youtu.be/oGAC-gBoX9k) and this book has been a huge assist in helping us flesh out survival mechanics and make the exploration pillar of DnD meatier and more fun. The book has been helpful with creating an emergent narrative and a beautiful map and building a solid player base that is hungry to explore our world and uncover the secrets we've hidden. West Marches play pushes DnD games to their absolute limits (in a good way) with encouraging use of items, mechanics, and smart roleplay to solve problems and really conquer a world and learn everything about it. The travel rules are invaluable for exploring both new and old territory. Making players take into account the area where they are resting, the conditions of the weather, their food and water situation, really makes them think more. The tables of weather affecting play are a stroke of genius. The worldbuilding chapter is really valuable for fleshing the starting town. The factions and encounter information and ideas are interesting and help keep the world far more varied from just, "cultists want to take over the world and summon a demon!" All in all, this book is freaking awesome. If you're gonna run a West Marches campaign, this is an essential tool. I bought the PDF and a physical copy and I'm still waiting on my print version to come in. Will update when I get it.