What is the order of operations in terms of invading?
Yesterday I drafted a 0 card that said before invading a planet discard the top card of your deck, add fleet strength equal to that card's energy cost to put in play.
My question is, before I do that ability, do I have to declare which planet I am attacking? Or can I adjust based on the result.
Similarly, do I have to play a card in an invasion, if I used the cost but didn't like the effect? Or can I just choose to have try the effect but not follow through with committing it to the attack?
Finally, when do you declare which cards you're attacking with?
You have to declare the planet you want to invade first.