Game and interactivity designers + scholars, Katie Salen and Eric Zimmerman have written a fantastic book called Rules of Play. I highly recommend the book to anybody interested in the topic. While their objective is to interrogate the world of play and games, much of the prose is appropriate for design in general.
As both a catalyst for blog posting and a foundation for thinking about the final project for the class, please read the following sections.
Unit 1: Section 3, Meaningful Play, pg 31-37
Unit1: Section 4, Design, pg 39-47
Unit1: Section 5, Systems, 49-55
Unit1: Section 6, Interactivity, 57-69
IIT students can access the entire book through, books 24×7 online … Here