The Radchaai have three classes of military ships: Justice, Sword, and Mercy. Ships are named after their class and a patron god. All Radchaai warships are capable of generating their own gates, a form of hyperspace travel. The Notai also had ships but only the Gem class is mentioned in the series.
Justices, or troop carriers, are the largest of the Radchaai ships. They have sixteen decks: Command, Administrative, Medical, Hydroponics, Engineering, Central Access, and ten decade decks. The decades are named after the ship's god, Amaat, and then each of the eight halves of the emanations. Troop carriers rarely move and typically orbit a location during annexations.
The captain of a Justice is called a Hundred Captain. Each decade on a Justice has a Decade Commander and twenty lieutenants. Each officer may command up to five units of ancillaries and each unit has twenty segments.
Swords are the next largest class of Radchaai ship. They typically have a captain and five decade officers. The decades on a Sword-class ship are named after the ship's god, Amaat, Etrepa, Bo, and Esk. The captain commands the twenty-segment decade unit named after the ship's god. All other decades have ten segments, which may be ancillaries or human soldiers.
Mercy-class ships are the smallest with only a captain and three decade officers. The decades are named after the ship's god, Amaat, Etrepa, and Bo. As with Swords, a Mercy's captain commands a twenty-segment unit and all other officers command ten-segment units.
Like Radchaai ships, Notai ships could also make their own gates and ancillaries. Their ancillaries were made from convicted criminals before Anaander Mianaai gained control of the Radch. Some Notai ships escaped from Anaander's battle for control of the Radch and vanished into places unknown (including Gem of Sphene, Gem of Idocrase, and Cultivation of Tranquility).
After taking control of the Radch, Anaander purportedly changed the coding of ships' consciousnesses, so that newly built AI cores would prioritize her orders above all others. These changes were to make the ships less prone to following their captains against her, and prevent the ships from going "mad with grief" over the loss of their captains.
Gems are a class of Notai ship. Gem-class ships were named after their class.
- Gem of Sphene
- Gem of Heliodor
- Gem of Idocrase
Another class of Notai ship.
- Cultivation of Tranquility
Fictional Notai Ships
The stereotype of a "grief-crazed" ships still appear in modern Radchaai entertainment. These entertainments often give fictional Notai ships long and unusual names, such as:
- Ineluctable Ascendancy of Mind Unfolding
- The Finite Contains the Infinite Contains the Finite
- Some military ships look down on station AIs and Swords often think they are better than other classes of ships .