I'd like my classes to feel distinctly game-like, so it's only suitable that the grades themselves are game-like. So far I've considered two ideas, and I'm trying to decide between them.
Method 1: Dance Dance Revolution scoring.
The class is out of a maximum of 1,000,000 points. A typical assignment might be 100,000 or so. Giving out awards of a few thousand here or there for class participation is easy, and it's more points than they'd get in all their other classes combined.
Method 2: Zelda scoring.
You start with a full health meter of 100 hearts. When you lose points on an assignment, your grade "takes damage". Extra credit provides "healing". You can keep track of your own grade on a life meter provided on the syllabus.
Zelda scoring is more realistic in that students always know exactly what their maximum possible grade is, and overall where they stand. But it can also be more demoralizing and intimidating since you're always losing points instead of gaining them, and it sets up an adversarial culture between me and my students since I'm dealing damage with every assignment.
Do you have a favorite? I'd love to hear your thoughts.