The Imperial Courier is the archetypal Imperial starship from both FE2 and FFE. It is probably the largest effective combat vessel in both those games as it provides a useful balance of speed and size. They are considered formidable opponents to relatively new players to the games.
It is closely related to the Imperial Trader, another starship commonly used by the Empire in both FE2 and FFE.
Considering the Empire's love for clones compared to the Federation's preference for mechanical artificial intelligence, a general surprise of Imperial designs is the high level of automation. When being designed, the Imperial Courier (first of its class, the Trader being second) was to have been extensively reliant on the use of genetically-designed slave crew. It was found, however, that the level of automation required to keep the two drives perfectly synchronised to the precision required by a hyperspace jump meant that it was simpler to just add the extra robotics.
Most ships of this size require a significant crew, but the Courier makes do with only three crew members, nominally a Captain (who is also an experienced pilot), a pilot First Officer and an engineer. Although most spaceports will not allow a ship to launch without the proper number of crew, the Courier can easily be flown single-pilot on a "milk run", however most commanders will find their job significantly easier with at least a pilot First Officer on board. Although highly automated, the ship is large and complex and should not be used for a prolonged period of time without an engineer on the crew.
The Courier has a unique two-drive system, and it is normally not possible to change the engine type. No reputable shipyard will remove a Courier's class 5 drive and replace it with another class since this invalidates the spacecraft's type certificate. However, some ship yards have been known to pair, bridge and modify two smaller drives and fit them to Couriers where the normal engines have been destroyed (typically in combat or due to lack of maintenance). In the few Couriers that have been modified in this way, typically a Class 6 drive is assembled by stripping two class 4 drives, bridging them, then fitting them to the engine nacelles of the Courier.