Dragon Age: Origins writer says the RPG series has a secret "overarching plan," but won't reveal the "very last plot" in case BioWare actually makes it

gamesradar.com:

Dragon Age's former lead writer and world creator David Gaider has revealed that BioWare knew all of the fantasy world's biggest secrets from the very beginning, but locked it away in a secret document that's still influencing where the series goes next.

Gaider was the lead writer on Dragon Age: Origins, Dragon Age 2, Dragon Age: Inquisition, and is often credited as Thedas' main architect, though he left developer BioWare to work on his own musical RPG well before Dragon Age: The Veilguard really took off. But despite his lack of direct involvement in the newest sequel, Gaider's work from decades ago is still shaping the series.

"By the time we released Dragon Age: Origins, we were basically sure that it was one and done," Gaider said in an interview with Eurogamer, "but there was, back when we made the world, an overarching plan." He calls it an "overall uber-plot" that explains Thedas' biggest question marks, contains "secret lore," and even outlines a possible, permanent ending for the beloved series - Gaider obviously doesn't say what that ending is, just in case BioWare actually decides to make it.

Much of that uber-plot was hidden away in Gaider's noggin for years, probably because the team weren't sure if they'd ever get to make a sequel. It supposedly stayed that way until Dragon Age: Inquisition got going, "and the writers got a little bit impatient with my memory or lack thereof," Gaider said. At that point, it was directly put into a secret "master lore doc" that was even hidden away from most BioWare staff. 

I've been hastily replaying Dragon Age: Origins to prepare for The Veilguard - the equivalent of doing Christmas shopping on December 26 - and it's kind of unbelievable how much of the series' future was teased and foreshadowed and lightly referenced from the very beginning. In-game codex entries might introduce one version of the ancient elven gods, for example, including Fen'Harel, who secretly turned out to be a major party member in Inquisition