Basically, it's a continuing cycle of entering a coin into a vending machine, with the next person to post saying what they get, and inserting their own coin. This is an example:
Player 1 wrote:I insert a coin.
Player 2 wrote:You get a can of lemonade.
I insert a coin.
The above is a very basic example. You can be as outlandish as you like, but I think it might be more in keeping with Knightmare if all the things dispensed are Knightmare, mediaeval, or fantasy-based.Player 3 wrote:You get a cup of tea.
I insert a coin.
So shall we have a go at it?
I insert a coin.