Transport Ships are a unit type in Rise of Nations. They are considered "meta units", as they cannot be built directly, and only appear in the game when any land unit tries to cross a body of water, in which case the unit will automatically embark on a Transport Ship and disembark after reaching a landmass (unless this option is disabled). However, a nation needs to develop Science 1 (Written Word) and own at least one Dock before land units are allowed to embark on transport ships.
As a nation progresses through the ages, transport vessels are upgraded automatically to newer models, thereby slightly increasing their hit points. There are three different transport ships:
- Transport Barge
- Transport Galleon (from Gunpowder Age on)
- Transport Freighter (from Industrial Age on)
Transport Ships have some unique characteristics: Their hit point, armor and speed are not related to the unit inside, nor can the unit use any attack, or benefit from any active or passive ability as long as it's within the transport. Also, when a unit embarks on the transport, its hit point percentage is transferred to it; this means that, for instance, if a unit with a third of its hit points embarks on a ship, the ship will, likewise, lack a third of its hit points. The reverse is also true: If a transport loses health, the unit will reflect on that damage after landing, so if the transport lost half its hitpoints on the way to the other shore, the unit will land with half its hit points.
Transport Ships are extremely vulnerable to attacks, especially from Light Ships, Submarines, Fighter Aircraft and land-based defense structures like Cities, Towers, and Forts. Therefore, landing operations should be well prepared (by clearing the coast line from defense structures) and protected.
Despite being so unique, Transport Ships benefit from a connected Copper resource (+20% hit points), and from Whales (+20% speed for sailing ships), like other Naval Units. Unlike naval units however, Transport Ships don't benefit from the ship healing bonus of Citrus. Instead, they can be healed/repaired by a unit with field healing ability, like Green Patriot, a French Supply Wagon, etc.
- Marines, the unique American Gunpowder and Modern Infantry line, fare better than other units in Transport Ships, having a movement speed and hit point bonus while embarked.
A land unit can be prevented from automatically embarking on a transport vessel by turning off the option Auto Transport (see left) in the unit's command box.
- Civilization V, released in 2010, employs a similar concept on sea transports, with land units moving into a sea tile automatically embarking on a transport ship. In all previous Civilization games the player was required to build transport ships and manually load/unload units.