The Ship Designer (Hotkey F9) is where players may create, update and customize ship templates and defense stations. All designs created or edited apply only to new shipbuilding orders, not to ships already under construction or in the fleet. However, a fleet can be ordered to upgrade at the nearest starbase with a shipyard in order to update its entire design. When it does so, each ship will upgrade to the latest existing design for its hull size that has a name identical to its current design name (e.g., a Victory-class cruiser will upgrade to the most recent "Victory" cruiser design). If there is no such identically-named design, it will upgrade to the most recent design for its hull size, whatever the name.
Many naval strategies advise that their empires deploy several types of warships to fill different tactical roles and face different opponents, and it is convenient for these to have different class names. Ships can be converted to and from such specialized designs and have different names by first making sure there is no design with an identical name and then saving the design the ship should upgrade to under the desired new class name, bumping it at the top of the ship design list for its size.
Clicking the Auto-Generate box on the lower left of the menu orders computer designers to continually update ship designs based on the latest technology research. Note that they do not take account of the enemies that the fleet is facing or may face, so it might choose components that an opponent can counter instead of a less up-to-date component that has proven successful. For example, the computer might auto-generate a design with an advanced laser that is statistically superior although the current enemy has heavily invested in shield technology that will heavily impair laser weapons but is vulnerable to attacks with the existing missile weapons.
Direct involvement in ship design is optional. An alert icon will appear if a ship design is obsolete, and a toggle enables automatic upgrading of components for player convenience. Stellaris can be played without touching this menu very often, but it is always advisable to be aware of the strengths and weaknesses of current and potential enemies.
Every ship design has an associated cost to build. This is the sum of the costs of its sections and components. All of them cost alloys and some advanced components also cost strategic resources.
Build time is determined by the ship type.
The base upkeep (per month) of a ship is determined as a percentage of its total build cost. Civilian vessels only cost Energy Credits as upkeep, while Military ships also cost Alloys. Upkeep is split into 2 parts:
Hull Upkeep: 1% of its build cost in Energy Credits and 0.333% of its build cost in Alloys.
Component Upkeep: around 0.833% of its build cost in Energy Credits and around 0.15% of its build cost in Alloys. Strategic Resource will also increase upkeep by a bit.
The hull of defense platform has no upkeep. The entire Ion Cannon has no upkeep. The hull upkeep of colossus is 0.3% of its build cost in Energy Credits and 0.1% of its build cost in Alloys.
Power is generated by the ship's reactor, as well as any Reactor Booster components the ship might have. Many components and subsystems require power to operate. A ship design cannot be approved if it has a negative power balance.
Excess power will give a small (at most 10%) and diminishing bonus to the ship's evasion, speed, and weapon damage. Specifically:
Each ship and station is made up of 1-3 sections, and each section may have its own design. Ship section designs vary based on where they are in the ship (bow, core, stern), while station section designs are all the same. Each section design has space for a variety of offensive and defensive modules. For example, one station section may be designed to carry a single large weapon or four small weapons.
To add an item to a module, click on the module (in the center part of the menu, identified by , , , , , , , , , , ) to see what items can be added.
All sections of the same type have the same utility slots, with only the weapon slots being different. Weapon slots trade at a fixed ratio, with the following being equivalent: