Rowboat is the bidding, trick-taking card game where trump changes throughout the hand. If you can play Spades, you can play Rowboat! First, you deal the cards face up until all 4 suits are showing (this is the tide). Next, you deal each player the same amount of card that are in the Tide. Next, you bid how many tricks you think you will take. Next, you start playing the cards in your hand on the cards in the Tide to win the trick. If you make your bid, you score points. However, if you miss your bid, you lose points.
This game is definitely for the 13+ crowd. However, if you've played any game using tricks, this is just a variation of that. It is something you can learn fairly quickly (it took me a couple of hands to figure out) and is a lot of fun! I'd recommend it for your next family party for the adults!