Emissaries is a trilogy of simulations about cognitive evolution, past and future, and the ecological conditions that shape it. Each simulation is centred on the life of an emissary who is caught between unravelling old realities and emerging weird ones. For artist Ian Cheng, the making of Emissaries became a lesson in Worlding-the unnatural art of creating an infinite game by choosing a present, storytelling its past, simulating its futures, and nurturing its changes. This book is for anyone interested in bridging the complexity of Worlding with the finitude of human psychology. Reflecting on his experience making Emissaries, Cheng derives practical methods for seeing and making Worlds as a whole-brain activity. To produce a World, one must summon the artistic masks who already live within us but rarely get to exercise their power. As we enter into a strange transitional era, Worlding becomes a vital practice to help us navigate darkness, maintain agency despite indeterminacy, and appreciate the multitude of Worlds we can choose to live in. Whether you are creating art, games, institutions, religions, or life itself: World to live!