During one of our Magic Tournaments (A very complex card game and A direct offshoot of D&D) we discussed and charted how Magic (card game again) and many other Popular computer games and Console gaming systems came about.
The whole chain of events as we could discern went through Gary Gygax's creation.
BTW D%D was spawned by the Writings of Tolkien C.S. Lewis and Lewis Carroll.
Amazing how such writings most of which were panned by the critics of their times turned into a Billion Dollar industry.
Actually, Gary always claimed that the various wargames that were available when he was young inspired D&D...not Tolkien.