Wide Game for 30+ people
Crepe paper cut into arm bands - large supply - different colour per team; Flag on stick/pole matching team colour
Split into teams of around 10 players per team. Give each team a large supply of crepe paper arm bands (1 colour per team) and flag of same colour. Each team to find somewhere to place flag that they can defend but also needs to be placed on ground (ie not at top of tree!). Once a base is placed it has to stay there, it can not be moved around during the game. Make sure you have a sensible impartial adult with each team to supervise. Each player gets arm band of their colour tied around upper part of arm over all clothing, in full view and accessible. Each player only allowed to carry one arm band at a time - none hidden in pockets! Idea of game is to attack other teams by attacking base and capturing flag (which if successful the attacking team receives 10 of defending teams arm bands and returns flag so game can continue). Players can also attack other teams players by removing their arm band. If you capture an aposing players arm band you keep it and the player who has had arm band removed is temporarily out of the game. This lasts until they return to their own base to get another arm band attached to their arm when they are then active in the game again. A player without an arm band can not take anyone else's band.
Game is played for a length of time determined before starting. At the end of the time limit the team with the most coloured band from opposing teams are the winners.
Plenty of adults needed - minimum of 1 to stay with each base and plenty to supervise the playing area for fair play.
If mixing sections together to play perhaps would be wise to add the rule that you can only take the arm band of a player in the same section to try and stop a group of Explorers working together to attack a Cub or similar situations!