Lots of questions on different subjects where you have to try to answer the latest question and if you are right then its your turn to ask the next question.
I was having dinner at a restaurant when an old lady at another table came over to me crying. She said I looked and sounded just like her son who had sadly died and asked me if I would do her a favour and say, "Goodbye mum" as she left to remind her of better times. I did this and it wasn't until half an hour later when I'd finished my meal that I realised that she was a con artist. How did I know?