You'll need a deck of cards.
The game is played in rounds until the players decide to stop. A round begins with a card being dealt to each player.
The player who has the highest card is the dictator (players cut the deck in the event of a draw). Once the dictator has been determined everyone hands back in their card.
The dictator then decides on a set of rules which apply to the cards in the deck (for example a black cards means take a drink, a King means down your drink etc.). A new card is dealt to every player and everyone must act according to the dictator's rules, except that whenever a rule applies to the dictator they may instead apply it to another player.
After everyone has performed the necessary actions the round ends and a new dictator is determined.