Students had to choose a page from their textbooks that we had studied before and make five questions on the that page. They then asked their questions to another group. If that group couldn't answer the question, they would lose a life (each team starting with 5 lives).
At the end of a round (once both teams had asked each other their 5 questions), the team with the most lives remaining were declared the winners are were rewarded with 15XP. Losers got 5XP, and if the round was a draw both teams got 10XP.
I will put up the full rules of this game at my project website here: http:///dendaienglish.wikispaces.com
Here are some pictures of the students in the midst of battle: