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

Hidden Hardpoints

At the end of a round of ground combat, you may discard 1 secret objective to have all your participating units enter coexistence; that combat ends in a draw. When another player ends your units' coexistence on a planet, you may draw 1 secret objective.
Tnelis SyndicateBreakthrough

At the end of a round of ground combat, you may discard 1 secret objective to have all your participating units enter coexistence; that combat ends in a draw.

When another player ends your units' coexistence on a planet, you may draw 1 secret objective.

SynergyPropulsionWarfare

Source: Discordant Stars