Living Card Game Mechanics
Here is an attempt to distill the core mechanics of a living card game. The objective of this little game is to get as many points (purple resources) in circulation before you run out of turns. Each turn you can spend the gold in your 'hand' to buy more gold, points, or actions. And you can spend actions to draw more cards. It illustrates the importance of finding the right mix of gold, points and actions to create the most efficient 'deck'.
Living card game mechanics have been recently popularized by the board game Dominion and has seen a few more implementations of late. It is mainly popular as a board game (mechanisms for board games ported to electronic devices), but I think it has much more potential. I would definitely like to see a mechanism like this ported to real-time video games.