World building in games involves everything from geography to culture. It can involve plants, waters, lands, animals, and the characters that live there, which may even be animals or plants or more!

You need to think about how a place feels, what has happened there, what might possibly happen during gameplay, and all of the connections that bring this world to life. How does the game system support the world (or worlds) depicted in the game?

In what ways can the player interact with their surroundings, ranging from making observations to collecting items to acting in reciprocity with (or reacting against) the places they traverse?

Whether or not all of the backstory and pieces make it into a game, asking yourself these questions and knowing the answers deeply will help inform all forms of narrative within a game.

Recommended Reading: Danny Wadeson's "Building a Universe" from The Game Narrative Toolbox. https://drive.google.com/open?id=1LzOjnDml2ZYgJGQgBG8OG9UER38O6QMA

Another Recommended Reading: Maurice Suckling and Marek Walton's "Environmental Storytelling" in Video Game Writing: From Macro to Micro. https://drive.google.com/open?id=1hIf8a73DxDKmqAjDmtlE_YDbpG8SJSDX

Wait, There's More!: Toiya Kristen Finley's "Livable and Believable, Despite the Limitations: Worldbuilding" in her book Narrative Tactics for Mobile and Social Games:
Pocket-Sized Storytelling. @toiyakfinley https://www.taylorfrancis.com/books/9781315155203

Are there any readings or presentations on world building in games that you recommend? Please share!