Age group(s) for this birthday party activity:
Elementary School

Cost of birthday party activity:
Minimal, costs are a little more for a tent if you don't already own one, or you can have guests bring one.

Birthday party planning information:
You'll need outdoor gear, such as a tent, and a BBQ grill if you can't have an open flame in your back yard. Guests will need to bring a sleeping bag. Ghost stories were told by a roaring "camp-stove" while s'mores were made.

Other suggestions or comments:
Games, such as a treasure hunt, were preplanned by using post-it notes and giving clues on each one for the next clue's spot ... at the end of the hunt was the cake. Other games included a water gun fight, and after that seemed to lose its appeal, my husband appeared dressed in an ugly halloween mask, running around while the kids shot at him. We also did the balloons tied to each ankle, while everyone tried to pop each others balloon, and the last one left won a prize.