On Tuesday, I gave the game design final. Students in small teams learned to brainstorm game concepts over the course of the last ten weeks. This time I threw in a few twists. Three times, I changed the requirements. Once, I had one student from each group rotate to a new group (to simulate losing a team member and having to train a new one). Towards the end, I suddenly reduced the time limit, and then added it back when it would no longer do any good.
The students loved it. They totally understood that this was inspired by real-world events, and that all of the new requirements were drawn from previous projects they had done. I was afraid I'd hear a lot of complaints of unfairness, but my fears turned out to be unnecessary.
I did hear of a similar mechanism from another game design teacher at GDC. Instead of having pre-scripted events like mine, she used a "wheel of misfortune" to choose events randomly. I prefer that solution as a way to deflect students' ire (if there is any) -- it's not my fault, it's the wheel!