Attaining the rank of Lieutenant Commander, users get their first duty officers. They will "enhance" your Captain but also fulfil assignments you uncover.
It's basically the gist of the entire Duty Officer System. They augment your Captain's abilities both in space and on the ground, but also undertake assignments that complete after a set time. These assignments require prerequisites and aren't always successful.
"It is intended to be as simple as it sounds, but getting the most from each assignment requires careful planning," explain Cryptic.
"Many assignments reward you for better combinations of duty officers, and the chance of a "normal success" versus a "critical success" is something you can manipulate according to which officers you choose to place on the assignment."
"Our goal with the Duty Officer System has been to make you feel truly like a captain, responsible for the success and well-being of your crew," added Geoff Tuffli.
Check out thefor a breakdown of the Duty Office System.