[zemo]

https://mitpress.mit.edu/9780262043915/elements-of-game-desi...

https://theoryoffun.com/

https://mitpress.mit.edu/9780262240451/rules-of-play/

https://www.sciencedirect.com/book/monograph/9780123694966/t...

https://en.wikipedia.org/wiki/Chris_Crawford_on_Game_Design

https://en.wikipedia.org/wiki/Game_Design_Workshop