Baldur's Gate

BioWare described Dragon Age: Origins as the spiritual successor to Baldur's Gate while it was in development, and built it to be one after losing access to the Dungeons & Dragons licence. What carried over:

• The party-based real-time-with-pause combat that Baldur's Gate invented, including the tactics system that automates what a player would otherwise pause for
• A recruited party whose members argue with each other and with the player, with approval tracked and romances available
• An origin story chosen at creation that changes how the world greets you, which is the Bhaalspawn premise generalised
• The structure: a central threat, a set of regions that can be tackled in any order, and allies gathered from each

The one deliberate break is the setting, and the reason is ownership rather than a lapsed licence. Greg Zeschuk of BioWare put it plainly: the Baldur's Gate and Dungeons & Dragons property is controlled by Atari and owned by Hasbro, so a direct sequel was never theirs to make. Thedas was built from nothing so that BioWare would own it, which is why this is an influence rather than a continuation.

Baldur's Gate is licensed Advanced Dungeons & Dragons, running the 2nd Edition rules as its engine, and that is the whole reason it plays the way it does. What is literally the tabletop game: THAC0 and armour class, the six ability scores, the class and level structure, spells memorised per day (Vance's mechanic, arriving by way of Gygax), saving throws, and the Forgotten Realms as the setting, with Baldur's Gate, Candlekeep and the Sword Coast taken from published campaign material. Filed HIGH because the debt is not thematic. BioWare's real invention was the pause-and-issue-orders interface that let a turn-based rulebook run in real time, and everything it was running was somebody else's rulebook.