This article is for the PC version of Stellaris only.
On the right side of the designer, one can select options for different subsystems of the ship. Most of them are required and it is not possible to design a ship without some version of them, but few of them are optional, having the option to install no subsystem in its slot.
A ship's reactor generates power for its other systems, and a new ship design cannot be created if it has negative power. Excess power slightly increases a ship's evasion, movement speed, and damage.
- Main article: FTL
This subsystem is optional, although without an FTL drive the ship is incapable of moving between systems.
Jump drives allow the ship to make a direct jump within a limited range. After jumping the fleet spends 200 days recharging, during which time it suffers -50% sublight speed and weapons damage.
This component predominantly improves fire-rate as well as various performance, like evasion, tracking, accuracy, or weapons range, depending on behavior type.
When in combat, every military ship will advance to within a certain distance of its target and fire its weapons, while staying at the intended distance. The engagement range is determined by the ship's designated role and will apply regardless of the effective range of the ship's weapons. Weapon range modifiers will also increase this range. Ships that have similar roles will typically cluster together, stay in formation with each other and attack in groups.
- Swarm: The ship will charge straight into point-blank range with its target, circle around it, and attack.
- Picket: The ship will move to close range (30) and attack from a position, attempting to intercept incoming enemy ships.
- Line: The ship will advance to medium range (50), assume formation and then attack everything within range.
- Artillery: The ship will stay at long range (80) and engage its target from far away. (Mostly applies against stationary targets, everything else is engaged as usual, i.e the ship will attack it as soon as it gets within range)
- Defense Platforms may somewhat reposition themselves around the starbase, but mostly stay in place and attack everything that gets within their range, dealing as much damage as possible.
The sublight thrusters determine how fast the ship maneuvers within a star system. They also increase the chance to evade enemy attacks in combat.
Sensors determine the ship's detection range on the galaxy map. They also increase tracking of all weapon systems, which is related to accuracy.
Sensor's Hyperlane detection range is always equal to 2 × Sensor Range.
This optional subsystem for Titans projects an aura around the ship which causes all enemy ships that enter it to suffer a penalty while giving a bonus to all friendly ships that enter it. While optional, they do not cost anything.
Multiples of the same aura do not stack.