I came up with some custom rules allowing certain ships to be fitted with a cloaking system. I tried my best to keep it balanced and simple. Starships with the ability to hide from other starships would add a lot of flavor for smuggling themed characters.
Cloaking System, Basic
10 BP; 20 PCU
A cloaking system allows a starship to temporarily become invisible and travel unnoticed through the depths of space. During starship combat, as an added option for the Divert engineer action, a starship’s engineer can send auxiliary power to their starship’s cloaking system. If the check is successful, during the next helm phase the starship moves at half speed (in hexes) and all opposing science officer checks against it have their DCs increased by 2 and during the next gunnery phase it gains concealment (20% miss chance) against all attacks. Starship weapons with the array ability ignore this concealment. The cloaking automatically ends during the next engineering phase unless the engineer of the cloaked ship succeeds with another Divert action, in which case the ship remains cloaked for another round. With enough successful Engineering checks using the Divert action, a cloaking system can keep a starship cloaked for a maximum of 5 rounds per combat before it must recharge for 10 minutes outside of starship combat. A starship with a malfunctioning or wrecked power core cannot activate its cloaking system.
Starship sensors in passive mode cannot detect an actively cloaked starship unless the cloaked ship still has its transponder on. During starship combat, active sensors on other ships can easily identify the hex a cloaked ship is located in as long as the cloaked ship is within the first range increment of those sensors. If a cloaked ship moves outside the first range increment of another starship’s sensors, those sensors are not able to know the hex occupied by the cloaked starship until it moves back into the first range increment of the sensors.
A cloaking system can be set to passive mode outside of starship combat, which consumes significantly less PCU, allowing the starship to travel undetectable by passive sensors while flying with thrusters or through the Drift. Active sensors automatically detect a ship in passive cloaking. When observed by a creature, a cloaked starship can be noticed with a DC 40 Perception check if it is stationary, or a DC 20 Perception check if it is moving. The GM may decide to make these checks lower if a starship is particularly loud or noticeable through other means.
Only Medium or smaller starships can be fitted with a basic cloaking system.
Cloaking System, Advanced
25 BP; 50 PCU
An advanced cloaking system works just like its basic counterpart, but it can also be installed on large starships, the DCs against science officer actions increase by 5 instead, and the concealment bonus increases to total concealment (50% miss chance).
- The engineer of a cloaked ship must continue using their action to keep the cloaking active each round, which is not a guarantee.
- I not 100% sure about making a cloaked ship move at half speed, but since they can still attack while cloaked, half speed would make it more difficult to move into optimal arc positioning.
- My thought was that huge or larger starships should be unable to benefit from cloaking due to their immense size and focus on offense. Limiting cloaking to large or smaller starships would give smaller ships (especially fighters and racers) another option for becoming effective in combat defensively and having an easier means of escape if they get into an unfortunate tangle with a dreadnought.
- Some added strategy would be if a ship fires at another ship with a tracking weapon that doesn't reach its target on the first round, the targeted ship could activate its cloaking system during the next engineering phase to have a better chance of the tracking weapon missing in the gunnery phase.
- The BP and PCU costs are high because a ship with a cloaking system would have to sacrifice more offensive potential for defense.
I'd appreciate any thoughts or feedback.
I like the basic idea, but maybe would make the PCU waaaay higher. In the sense that you will have to stop using other things in the ship while the stealth system is online.
In my Starships, Stations and Salvage Guide by Ed Moyer, 3PP supplement for Starfinder, we have a tech based cloaking device which offers in reduction in detection and temporary hit points. But the guide also offers a more effective arcane (technomancer) defenses, including a Spell-Primed Shield Bay which can grant abilities like a limited Mirror Image (holographic image), invisibility, greater invisibility, even a limited Blink stunt and many others, that is more expensive BP wise, but better than just a cloaking device.