Updated Aug, 12th 2013
Carcasonne is one of my favourite games, it's simple to explain and easy to learn, but there's still plenty of room for strategy and even to mess with your opponent if you draw the right tiles.
I also like games like Betrayal at House on the Hill where you make the map up as you play.
My idea is a card game where players use the cards to construct space ships which they then use to battle each other.
Players start with a command room and draw and play cards to build and expand their ship. In order to attack you opponents ship you will need to add weapons rooms to your ship. To block incoming attacks you will need to add shield generators to your ship. However, you can't activate your weapons or shields unless your ship has a engine room that you can use to power them. The more engine rooms you have the more weapons you can fire or the more shield you can use. The catch is that if you allocate all your power to your weapons, it will leave you vulnerable to return fire as you won't have any power left to activate your shields.
If your attacks are not blocked by your opponents shields, then you cause damage and they must remove cards from their ship.
The game ends when one of the players' ships is destroyed or one of the players surrenders.
So I printed out a number of colour cards so I could try playtesting a simple version of this concept. I used a white card to represent the captain/command centre which each player would start building their ship from. I used red cards to represent the weapons rooms. Blue cards to represent the energy generating rooms. Black cards to represent the shield rooms and yellow cards to represent hallways. So it was very, very abstract and the structure that we made didn't really end up looking like space ships at all, which is something I'm going to have to work on. No point having a spaceship making game if you don't make a spaceship.
Initially we played where the weapons, energy and shield cards could only be connected to hallways. This worked okay... but i think i included way too many hallway cards. It took ages for either of us to place enough energy and weapons cards to actually do any sort of damage to each others ships.
The next time I reduced the amount of hallway cards and we played where you could attach the the cards to any other card. This was a bit of a disaster. It basically made the hallways useless and players had way too many energy, shield and weapons cards. I found that if one player has enough energy and sheild cards, there is pretty much nothing the other player can do to damage his ship. I need to find a way to balance the amount of these cards that players have access too, so that players have to really choose between attacking and defending.
I think making the speciality rooms have to be built off hallways isdefinitely better than just being able to place tiles anywhere. ... I also need to make it more difficult to lay the cards, or at least restrict where the cards can be laid. I also need to figure out a way to make the cards actually look like a ship.
I'd welcome any suggestions.
Thanks for the feedback guys. It was very helpful. I was trying to think of some way to limit or restrict the way different cards can be connected, and I think the connection ports might definitely solve that problem. I also like the idea of constructing fleets of ships. Maybe the game should play out in two distinct phases.
1: Shipbuilding. War between the planets is declared and the race is on to construct a fleet of ships with which to wage war. Players can either construct lots of little ships, or try to construct a massive ship but risk not being able to complete it in time.
2: The Battle. The fleets attack and the last player with ships remaining is the winner.
I might have to work out a more in-depth combat system too. Not too complex, I want the game to be quick and easy to learn and play. Maybe just something as easy as rolling a dice to see how much damage each attack does.