This is one of those Minute-to-learn-Lifetime-to-master games in that the rules are really quite simple. There are stacks of cards in front of all the players. Some represent money (needed to buy more cards), some represent points (needed to win), and others are Actions (used to help you get more money, or points, or cards, or to screw your neighbors over)
Everyone starts with the same deck of 10 cards, on your turn you draw 5 and use what you can and discard the rest. Buy more cards for your deck however you see fit, shuffle your discard pile whenever your deck runs out. When three piles of the cards are gone, the game is over and everyone counts up how many points they had in their deck of cards to determine a winner.
When you boil it down like that, it kind of sounds simple minded but really it is quite the opposite. Its apparent simplicity is only a facet to its brilliant complexity. Anyone who has played Trading Card Games like Magic:The Gathering can appreciate the intricacies of the deck-building process. Dominion is essentially making deck-building the game itself.
This is a glorious game and the game is never the game twice. There are plenty of different game types which create different flavors of the game by including and excluding certain card types. It really is a blast, and it is certainly the best new board game I have played this year.
I highly encourage you to check it out.
Additional details can be found: here.