In modern-day arcades, pinball machines are widely considered four-legged, glass-topped dinosaurs. They represent portals to an era before Xbox and PlayStation. Even before Ms. Pacman and Donkey Kong, there was the zip, ding, bonk, boing, thunk and clack of pinball machines.

Yet there was a time — starting in the 1930s — when they were at the forefront of entertainment for millions of people with coins to spare and time to pass. Along came Steve Kordek, a game designer from Chicago who revolutionized pinball in 1948 when he introduced a pair of flippers at the bottom of the machine. It changed the way the game was played.

Mr. Kordek, who died Feb. 19 in Park Ridge, Ill., at 100, was credited with developing more than 100 pinball games, including the bestsellers Space Mission and Grand Prix. Yet his most enduring contribution was the dual flippers.

Pinball historian Roger Sharpe said every pinball game designed since has incorporated Mr. Kordek’s flippers.

“It really liberated the game designers to start thinking of the entire play field in a different way,” Sharpe said in an interview. “It changed strategy fundamentally and allowed you to have this landscape that was much broader in scope than what had been done before. It empowered the player to a much greater degree.”

Steve Kordek in a 2009 photo next to two pinball machines he kept in the basement of his home on the Northwest side of Chicago. (Alex Garcia/CHICAGO TRIBUNE)

Pinball traces its history to the 18th-century French game Bagatelle, in which players used billiards’ cues to navigate a ball around a board with pins.

Modern pinball for most of its early history had been a game of chance. In the early 1930s, a movie projectionist and tinkerer named David Gottlieb invented the first pinball machine in Chicago. The object of the game was to roll a ball toward holes with different point allotments. Luck alone dictated where the balls would fall.

At a penny per play, pinball proved immensely popular during the Depression, when men would wager on the outcome of the games.

The practice so enraged New York Mayor Fiorello LaGuardia that he outlawed the machines. His goal was to slim the pockets of pinball proprietors, whom he called a “slimy crew of tinhorns, well-dressed and living in luxury on penny thievery.” (In 1976, the machines were officially made legal again in New York.)

Flippers made pinball more of a game of skill. They were first introduced on the 1947 Gottlieb game Humpty Dumpty, which had six flippers. Humpty Dumpty was an immediate success and sent other gamemakers into a frenzy to copy it.

Mr. Kordek, then working at the Chicago-based pinball company Genco, was tapped to design his firm’s entry into the flipper market. Confined to a small budget, Mr. Kordek opted for two flippers, instead of six, and placed the pair strategically at the bottom of the play field, near where the balls filtered into the drain.

At a 1948 pinball trade show, Mr. Kordek’s game with the defensive flippers, Triple Action, was the biggest hit.

“It changed the game considerably,” said David Silverman, curator of the National Pinball Museum in Baltimore. “The goal of the game is control over where the ball goes. By putting flippers down there, there was much better control and a much wider field to shoot the ball in.” (Silverman pointed out that the flippers, as was the style of the time, faced outward. The flippers were later pointed inward.)

Mr. Kordek left Genco in 1960 and began working as director of game design at Williams, one of the country’s top pinball machine manufacturers. There, Mr. Kordek served as a mentor to many of the game’s up-and-coming designers, including Pat Lawlor, who developed the mega-hits the Addams Family and the Twilight Zone; and Steve Ritchie, who designed Terminator 2: Judgment Day.

Steven Frank Kordek was born Dec. 26, 1911, in Chicago. After high school, he was a forest ranger in Idaho with the New Deal-era Civilian Conservation Corps. In the late 1930s, he was hired to perform soldering work at a Chicago factory owned by Genco.

His wife of 62 years, Harriet Kordek, died in 2003. His daughter Donna Kordek, of Naples, Fla., confirmed Mr. Kordek’s death but did not disclose the cause. In addition to his daughter, survivors include three other children; two brothers; one sister; six grandchildren; and nine great-grandchildren.

After he retired in 2000, Mr. Kordek revealed his secret to a good pinball game.

“What attracts a player, first, is the pictures on the back glass of the game. Second, if what he sees on the play field is different, that’s a success,” he told the Chicago Tribune in 2009. “And when the features are so exciting that he wants to put more money in it, you’ve got him.”