As anybody who frequents chat knows, I freakin' love puzzles. Everybody loves puzzles! But there's a lot of crap out there, and there's nothing more annoying than spending hours steaming your noodles only to find that it's some kind of lame trick question. So I thought it'd be a good idea to create a thread where we can share really good ones and tackle them together. Puzzles involving creative or clever thinking are what we want. There should be one answer, and you should know it when you get it. The best ones should seem impenetrable, until you receive a sudden flash of inspiration. Word riddles are fine, as long as they satisfy the above. I'll post a few favourites off the top of my head to get the ball rolling. Please don't spoil any you've seen before.


The field and the farmer

You love sweetcorn. You're sat in the middle of a circular sweetcorn field, eating some sweetcorn. There is a path around the circular sweetcorn field, upon which rides an angry old sweetcorn farmer with a pitchfork, on a tricycle. The tricycle moves 4 times as fast as you do, but it cannot go off-road. Can you definitely escape?


The prisoners and the light

There are 20 prisoners in a prison. The warden of the prison is slightly insane, so one day, he takes all the prisoners outside into the yard and tells them the following. From now on, once every day, he will select a random prisoner, and take them from their cell to a disused bathroom. In the room is a switch; this switch turns the room's light on and off. Then he'll take the prisoner back to their cell. At any time, any prisoner may say to the warden, "we have all been to the bathroom now". If that prisoner is right, they're all freed. If the prisoner is wrong, they're all fed to the prison dogs. They all have an hour to talk to each other and form a plan, before they're taken back inside the prison, where they can't communicate. What do they do?


The coins and the table

You are blindfolded in a room with a table in the middle. Scattered across the floor are several thick gold coins. You're told that half are heads up and half are tails up, but you don't know and can't tell which each individual coin is. To win the coins, you must put some of them on the table, in such a way that the number of heads on the table is the same as the number of heads on the floor. Can you do it?