“...Informal, unplanned games organized and played by children ...”
My kids have an overbearing teacher on recess duty most days, who tries to referee every freakin’ game they play. (She also wants all the kids to face the same way while on the swings. I digress ...)
So they invented some new games ;-)with very flexible rules.
Creative acts of rebellion are always the best (and the most satisfying), especially when those against whom they are directed cannot perceive their true meaning.