There was a wonderful game that I played growing up while in school and college called Just A Minute. In fact, it was so popular in that part of the world that we had inter-school and inter-college competitions. The rules of the game are very simple – you have to speak on an impromptu topic for one minute without hesitation, repetition, or deviation while maintaining grammatically correct English. One of the other competitors can challenge you and take the podium from you if you trip up. Besides the obvious entertainment that the game provides, it is an excellent way for kids to develop the skills of public speaking, story telling, collecting and sequencing ideas, and expanding their knowledge and vocabulary.
The game has been a very popular BBC Radio show for decades.