There is an enemy planet I want to attack but 2 of the players guarding it are also in my legion.

My question is what happens to those legion/ally ships of mine? Do I attack them? Are they ignored? Do artifacts work on them?

I could easily take them all out because it takes 4 of them to match me in level and firepower. Just trying to figure out the best strategy.

You are targeting a 'Legion Ally Occupied' planet. Since you cannot attack members in your legion, you have a few options:

* Ask your legion members to stop guarding it (get them to guard something else)
* Use unstable wormhole emitters

This situation is more political than strategic - your legion might not be so happy that you are trying to take a planet owned by one of their friends.

Unfriend them. Fascism is politics too.

Hahaha roflcopter!!! So true

/concur
but srsly.....get a smaller pic