Glad to enlighten you, Sted.
Here's how I do it at my Thursday quiz night:
People buy raffle tickets for £1 each. Later on, I drawn out a ticket & that person comes up to play the game (while I play the theme tune). They mix up the cards, then I deal 8 cards face down onto the board in two rows of 4.
They have to turn over all cards correctly by predicting whether each card will be higher or lower than the previous one. If they turn over all 8 cards correctly, they win the jackpot. If they don't win, the money rolls over to the following week, and keeps rolling over until it's won.
They have the option to change the first card if they want to, Aces count high and if a pair comes up the game is over.
Hopefully that covers everything.