The son of a Boston cabdriver, Adelson came from humble beginnings. In interviews, he's joked that he can't describe his life as a rags-to-riches story because his family was too poor to own rags.
An Army veteran, Adelson made part of his fortune in the trade show business. He developed Comdex, which, in the 1990s, was the world's largest computer show. He sold that company in 1995.
He got into the casino business in the late 1980s, when he bought the Las Vegas property housing the Sands Casino, known as a favored haunt of Rat Packers such as Frank Sinatra and Sammy Davis Jr.
Despite its storied past, the Sands was struggling at the time of Adelson's purchase. It couldn't compete with newer, flashier hotels.
By 1996, Adelson began attacking the Sands' woes: He demolished it. That year, the hotel was imploded to make way for a new hotel and casino complex. Three years and $1.5 billion later, the Venetian opened. Its indoor shops and canals were said to be inspired by Adelson's honeymoon in Venice with his second wife, Miriam.
"It's absolutely beautiful," Fischer said. "You can't complain about the money that he spent there."
Less picturesque, however, was Adelson' relationship with fellow Vegas mogul Steve Wynn. Both men, he said, have purchased parking lot properties that the other had wanted. As a result, some of their employees have to park relatively far away from their respective hotels.
"I would assume they go out of their way to annoy one another," Fischer said.
Adelson has also been involved in various lawsuits, including one filed against him by his two sons over a stock deal. The court eventually ruled in Adelson's favor, finding that "Adelson, although perhaps lacking paternal kindliness and, indeed, cordiality generally, did not mislead, cheat or defraud" his sons.
As with other casino operators, Adelson's gambling future remains uncertain. He's seeking to raise $2 billion from Asian banks to finance his Macao developments, according to published reports. He also recently invested an additional $475 million in Sands but the move did little to bolster the sagging share price.
However badly his company is hurting, however, Adelson himself seems to be doing OK -- he's still worth $11 billion, according to Forbes magazine.
As for that latest $475 million investment? He told The Associated Press that it "hasn't changed my lifestyle."
ABC News' Melissa Lenderman and Barbara Paulsen contributed to this report.