Former Bethesda VP of PR and Marketing Pete Hines recently spoke with dbltap and shared his memories of working. In particular, he spoke about the creation of The Elder Scrolls 4 Oblivion.
He recalled Todd Howard's philosophy - the creator said that "great games are played, not created."
Pete Hines explained this philosophy: "that is, your every idea of what is good and what is not matters only when someone starts playing - that's what determines whether you succeeded or not."
In search of a good solution, Howard iterated the combat system, and marketers tried to find reliable advertising material:
"In Oblivion, the combat system was changed three times during development. Therefore, we tried not to talk about how the combat system works [in advertising], because we didn't even know if we had the final version. Therefore, we tried to bet on those parts of the game that we thought would resonate with people."