The object of the game is to accomplish one of 3 goals:
These goals are accomplished by playing cards. A card has a cost -- in order to play it, you must pay that many resources -- and an effect -- for example, it might cause six points of damage to your enemy's vessel.
- Complete your FTL vessel,
- Destroy your opponent's vessel, or
- Reach a critical mass in one of the three resources: power, hardware, or spies.
An example card might be:
To play the BIOMASS card, you must pay the cost, 7 power. The effect is +9 cloak, -5 spies.
Those poor, poor spies.
Note that you don't pay five spies as part of the cost -- this distinction is important; if you play the card when you have less than five spies, you will be reduced to zero spies, not a negative number.
In other words, you must have enough resources to cover the cost of the card, but negative effects of the card will only be levied if possible.
Each turn, you may gain some of each resource, based on how many generators you have: each turbine generates one power per turn, each factory produces one hardware per turn, and each academy graduates one spy per turn.
If, for example, you have one turbine, two factories, and three academies, then each turn you will receive one power, two hardware, and three brand-new spies.
Another example card:
Hope those spies are good teachers.
This card will have the net effect of, starting next turn, providing you an additional spy each turn. It will pay for itself within three turns; everything after that will be profit. Woo-hoo.
Beyond your generators and resources, there are two more things you need to keep track of: your cloak and your vessel. The cloak acts as a barrier between your enemy and your vessel; any damage indicated by a card will, unless indicated otherwise, be applied first to your cloak, and, only when your cloak is gone, to your vessel. Since having your vessel reduced to zero loses the game, having a sizeable cloak is often a necessity.
A third example card:
This card will do seven damage to your enemy. If his cloak is seven or more, it will be reduced by seven points. Otherwise, his cloak will be reduced to zero, and his vessel will be assessed any remaining damage points.
A player's turn consists of playing (or discarding) one card.
That's it for the overview. If you're interested in helping to design cards, go on and read the design guidelines.