Its a real time strategy game where you play a pirate and you goal is to control the majority of the towns and then you win the round. You can do 1v1, 2v2 & 3v3. You can play online and split screen multiplayer as well.
One cool thing about Age of Booty is that its accessible enough for my wife and I to play together. Its not a terribly deep game so we don't play it a lot, but when we do its quite fun. One nice thing is that all the extras for the game are free. Basically they have made available a bunch of extra maps, often community create for you to download. That really adds to the replayablility of the game.
If you are looking for a good pick up and play RTS game with a pirate theme, Age of Booty is a fun choice.