That's a simple question with a complex answer. What role are you playing in your daily life?
I could rattle off a biography of my character, from his origins as megacorp company man (Cosi Holdings, born and bred, going back at least twenty five generations and possibly as far back as it's origins on Earth), to joining the Pilots Federation for a shot at living his dream as a freelancer, to his disillusionment with that organization when he became aware of just how far it's corrupt authority spread...and that they'd never let him leave. I could talk about how he's often found himself a mercenary profiting from all sides in conflicts, with the full knowledge of the powers that be among all those sides, who readily collude with each other to maintain power at the expense of those beneath them. I could describe the atrocities hes committed as a black opperative to fast track his advancement in military circles. However, I'd have to write a book to capture a complete picture of his motives and the mutable 'role' he grudgingly plays.
Ultimately, I play a Pilot's Federation Commander whose already gotten ahead and has some regrets about the methods, but who won't trade what freedom he's got left, or the comforts he's won, for anything. He mostly minds his own business, subtly (or not so much) undermining (preferably to death) those he percieves as threatening that comfort and freedom. Self-preservation is his prime motive (and I play him as someone who isn't quite sure that ejection seat will always work) and in a complex world, that makes for a complex role.