I took the chance to experience such an event at least once in my life and for now I can say that this surely won't be the last time.
We were 22 people and split up to four teams, two 5-people and two 6-people. Then we pulled up some sort of tournament where each team played two games against each other team and the team with the most wins... well, wins.
Personally I think I've been quite successful and although we didn't explicitly make out a specific tactic in our team most rounds went the way that the other members of my team stayed back and covered the other team in colorful shots while I was going forward at the side of the playfield taking out one enemy after another.
I don't know why I've taken out much more other players than I have been hit myself. Perhaps it is either because our enemies didn't recognize me sneaking up to them or my body shape doesn't make a good target.
Well, a few times some players from a 'non-amateur' team played in the playfield and I don't think we would have had a chance of staying in the field longer than a few seconds against even only one of them...