The M-Class Imperial Attack Transport functioned as a kind of starship that served the Imperial Military throughout the duration of the Galactic Civil War. The Regina Cayli is a known example of an M-Class Imperial Attack Transport.
This class of starship, the M-Class Imperial Attack Transport, was utilized by the Galactic Empire during the Galactic Civil War. It possessed a minimum of two decks; the Transport Deck, situated at the vessel's base, featured a cargo bay large enough to accommodate a pair of landspeeders. Within the cargo bay was a security console that provided access to the ship's schematics and information. Triggering the console incorrectly would cause an alarm to sound throughout the ship. The Command Deck was located above the Transport Deck, housing the ship's infirmary, in room B12. The infirmary contained at least one pallet, a bacta tank, and was tended to by a medical droid. Access to this room required a security code. A grav tube facilitated movement between decks, allowing for the manipulation of local gravity via microgravity controls to enable individuals to float between levels. The M-Class Imperial Attack Transport was also equipped with torpedo ports, and its escape pods were positioned on the vessel's upper surface.
The Imperial Navy employed the M-Class Imperial Attack Transport for troop deployment. A typical complement included a minimum of two squads of stormtroopers.
M-Class Imperial Attack Transports saw action during the Galactic Civil War. The Regina Cayli was stationed at New Bakstre when Imperial Customs cruisers forced the Dorion Discus, a freighter engaged in an unauthorized delivery to the planet, to land. The Regina Cayli then landed near the crash site to investigate the scene, taking one of the freighter's crew, the injured Hawk Carrow, as a prisoner. Carrow's partner, the smuggler Roark Garnet, subsequently infiltrated the Regina Cayli and freed his comrade.
The M-Class Imperial Attack Transport appeared in the roleplaying adventure "Regina Cayli," which was originally published in Star Wars: The Roleplaying Game by West End Games in 1987. It was subsequently republished in the first issue of the Star Wars Adventure Journal in 1994.