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

Obsessive Designs

During the action phase, after you research a unit upgrade technology, you may use the PRODUCTION ability of 1 of your space docks in your home system to produce units of that type, reducing the combined cost of the produced units by 2.
Zelian PurifierFaction ability

During the action phase, after you research a unit upgrade technology, you may use the PRODUCTION ability of 1 of your space docks in your home system to produce units of that type, reducing the combined cost of the produced units by 2.

Source: Discordant Stars