Dragon Age Origins ends with a ritual that Morrigan offers as an alternative to the Grey Warden’s required sacrifice: a dark ritual using Old God magic that preserves the Warden’s life at a cost she does not fully explain. The ritual requires the Warden’s consent and cannot be forced; refusing it means the Warden dies performing the killing blow.
Morrigan’s explanation of the ritual omits that the child she conceives will be a vessel for the Old God’s soul — the Architect’s goal, the thing the Darkspawn are unconsciously pursuing. She is not lying; she is selecting. She tells the Warden the outcome for the Warden, not the outcome for the world.
BioWare built the ritual as a test of whether the Warden prioritises survival over consequence. Players who accepted the ritual received an ending that felt complete; the consequence deferred to Dragon Age Inquisition, where Morrigan’s child appears as a fully grown young man with unusual power.
The Morrigan mirror in her home — a magical scrying object she is unusually protective of — contains a spirit connected to the ritual. Players who destroy the mirror before learning what it is lose access to a dialogue thread that explains the ritual’s true mechanism. BioWare built a pre-condition into the game’s largest optional choice.

This is the kind of discovery that keeps communities alive for years. Well documented.
Really fascinating breakdown — I had no idea this was hidden in plain sight the whole time. Going back for another playthrough immediately.