Twilight's Fall – a separate game. Twilight Imperium's expansions, mods and rules topics are not part of it.

Shrouded Skirmishers

At the start of a space combat, you may choose 1 of your ships in the active system that did not begin this action in that system; roll a die. On a result equal to or greater than that ship's combat value, produce 1 hit; your opponent must assign it to 1 of their ships.
Kollecc SocietyTechnology – Propulsion

Propulsion

At the start of a space combat, you may choose 1 of your ships in the active system that did not begin this action in that system; roll a die. On a result equal to or greater than that ship's combat value, produce 1 hit; your opponent must assign it to 1 of their ships.

Prerequisites: Propulsion

Source: Discordant Stars