Double Fine's Lee Petty took to Twitter today to share a copy of the (spoiler-rife!) casting document he wrote last year to help guide development of the studio's funky space platformer Headlander.
It's worth a read, especially if you're interested in game development, since there are few public examples of these types of design docs for fellow game devs to learn from -- Petty himself points out that this is the first one he ever wrote, and he didn't have many examples to study.
While the term "casting document" is more commonly used in TV and film production than in game development, what Perry has shared (embedded below) is effectively a Headlander pre-production design bible.
The roughly 22-page design document lays out the game's theme, its setting, and its various characters, replete with their motivations and some sample dialogue..
HeadLander Casting Document by Lee Petty on Scribd