The Rap Battle works best with 3-6 groups. The facilitator starts by blindly selecting one card. Each group now has three minutes to solve a challenge with that card. After three minutes every group presents their best (or funniest) idea. The facilitator hands the Brain Fuel card to the group with the best idea. That group receives a point. Ready for the next round? Go!
PS: Don't forget to turn on some rap music to get in a battlin' mood!