Hi!

What´s the difference between uncommen, commen and rar officers?
and if there is a difference should i take the best one with me?

greets
Nythra

The uncommons and rares will have something enhanced that a common one won't, what the special something is randomly generated, and you'll need to look at what they come with to try and figure out what it is. In some lucky cases, the special something might be of use to you... in most cases probably not - you can sell those uncommisioned officers to others in the exchange - they may need the special something, and you can shop for a better BO yourself.