Ralph H. Baer, who turned television sets into electronic fantasy lands by inventing and patenting the first home video game system, died on Saturday at his home in Manchester, N.H. He was 92.

His death was confirmed by his family.

Video games have become more than just a ubiquitous pastime and a gigantic market (by some estimates, total worldwide sales of console hardware and software and online, mobile and computer games exceeded $90 billion in 2013). They are also an engine that has driven scientists and engineers to multiply computer speed, memory and visualization to today’s staggering capabilities.

Flash back to the sultry late summer of 1966: Mr. Baer is sitting on a step outside the Port Authority Bus Terminal in Manhattan waiting for a colleague. By profession, he is an engineer overseeing 500 employees at a military contractor. Today, a vision has gripped him, and he begins scribbling furiously on a yellow legal pad with a No. 2 pencil.

The result was a detailed four-page outline for a “game box” that would allow people to play board, action, sports and other games on almost any American television set. An intrigued boss gave him $2,000 for research and $500 for materials and assigned two men to work with him. For all three, as they plowed through prototype after prototype in a secret workshop, the project became an obsession.