The digital technologies of the 21st century are reshaping how we experience storytelling. More than ever before, storylines from the world's most popular narratives cross from the pages of books to the movie theatre, to our television screens and in comic books series. Plots intersect and intertwine, allowing audiences many different entry points to the narratives. In this sometimes bewildering array of stories across media, one thing binds them together: their large-scale fictional world. _Collaborative Worldbuilding for Writers and Gamers _describes how writers can co-create vast worlds for use as common settings for their own stories. Using the worlds of _Star Wars_, _Lord of the Rings_, _A Game of Thrones_, and _Dungeons & Dragons_ as models, this book guides readers through a step-by-step process of building sprawling fictional worlds complete with competing social forces that have complex histories and yet are always evolving. It also shows readers how to populate a catalog with hundreds of unique people, places, and things that grow organically from their world, which become a rich repository of story making potential. The companion website collaborativeworldbuilding.com features links to online resources, past worldbuilding projects, and an innovative card system designed to work with this book.