If our goal is participation I think that competition should be a team effort. Having only person as the house champion while canon leaves to many people on the sidelines if this is going to be out main focus for the term beside classes. I like the suggestions that the tasks be RPed centered. Each task could be posted and the students submit their "entry", then a panel of judges (new ones for each task perferrablly) award points.

Teams could be limited to 10 players the first round with the 3 lowest scores being dropped for round 2 when the teams contain only 7 players. The final challenge could have 4 members. Numbers could be adjusted once we see how many sign up.