I'll put in a plug for his book Theory of Fun for Game Design (https://www.amazon.com/Theory-Game-Design-Raph-Koster/dp/1449363210 https://www.amazon.com/Theory

I'll put in a plug for his book Theory of Fun for Game Design (https://www.amazon.com/Theory-Game-Design-Raph-Koster/dp/1449363210 https://www.amazon.com/Theory-Game-Design-Raph-Koster/dp/144...). It's a great read that's accessible but also deep and thorough.