The 400 Project

There's a great column in Game Developer magazine called "Better by Design," where they try to enumerate the building blocks of good game design. Now, there's a web site that serves as the home for these ideas called the 400 Project. The goal is to get 400 rules of good game design.

This ties in very closely with the idea of "Design Patterns" - conceptual building blocks designed to solve problems that recur in tough design projects. Whether or not you end up using them in your design process, it's a good exercise to go through them and be aware of them, because it makes you think concretely about the effect - positive and negative, obvious and subtle - that the decisions you make during design can have on the gameplay.