: Players scavenge their ruins to survive the current apocalypse.

: They built the interstellar infrastructure humans now use.

: Their disappearance is linked to the terrifying extra-dimensional invaders.

: The game hints that the current war has happened before. Key Themes

: Much of their true intent remains buried in encrypted logs.

The text you are looking for likely refers to the expansion or DLC titled The Precursor Legacy .

: Humanity struggles to master tools they didn't create.

The Precursors are the architects of the jump gates and the massive starbase. Their "legacy" in the game is one of both immense power and cautionary mystery.