An old activity which can be used in class as a warm-up or revision exercise. It has a lot of different possibilities, not only practising vocabulary. Actually, you can revise anything you want with your students. You may ask them to give definitions, to make sentences, dialogues, or stories, to give one or five examples, to speak, or to write. You can practise all sorts of vocabulary or grammar, but also language functions or different skills. There are no limits here. And the best option is to ask your students to prepare their own games. Have fun.