There are four species in the original Sword of the Stars. New races are introduced in Expansion Packs. Each species have their own technology tree (with research probabilities and technologies specific to each race) and language.
Human[edit]
Human ships travel by nodes. While this allows them to quickly travel across star systems, their drives function only along node paths, allowing them to be blocked by choke points. Traveling on a node requires each ship in a fleet to have enough fuel to complete the jump, since they cannot be refueled in transit.
If necessary, human ships can use slower-than-light travel to reach other systems.
Tarkas[edit]
Tarkas ships travel by a faster-than-light drive. As such, they can travel directly between star systems.
Hiver[edit]
Hiver ships only have slower-than-light drives. Instead, they rely on gate ships placed within each system to instantly transport ships from one system to another.
A technology upgrade gives hivers the ability to teleport ships without a corresponding destination gate.
Liir[edit]
Liir ships travel using a stutter drive, teleporting the entire ship minuscule distances repeatedly. Gravity wells impede these teleportations, therefore Liir ships travel faster the further away they are from any stars or planets; their fastest point is in the middle of their flight.
Zuul (Born Of Blood Expansion)[edit]
Zuul ships use nodes like Humans, however they create their own by using special Tunneling Ships that rip a new node line. These node lines decay over time and will destroy any ships using them when they collapse.