As a writer and editor, Lee was the key to Marvel's ascension to a 1960s comedy series when he, in collaboration with artists such as Jack Kirby and Steve Ditko, created super heroes that would attract generations of young readers.
"He felt an obligation for his fans to continue to create," his daughter JC Lee said in a statement to Reuters. "He loved his life and he loved what he did for his life. His family loved him and his fans loved him. He was irreplaceable."
She did not mention Lee's cause of death, but the TMZ celebrity website said an ambulance was called to Lee's Hollywood Hills home early Monday and that he died at Cedars-Sinai Medical Center.
The Americans were familiar with superheroes before Lee, partly due to the 1938 launch of Superman by Detective Comics, the company to become DC Comics, Marvel's archrival.
Lee was generally credited with adding a new layer of complexity and humanity to super heroes. His characters were not made of stone – although they seemed to have chiselled from granite. They had love and money worried and eradicated tragic shortcomings or feelings of insecurity.
"I thought it would be fun to learn a bit about their privacy, their personalities and show that they are both human and super," Lee told NPR News 2010.
He helped to design the superheroes, but he took full ownership of them.
His creations included web-streaming teenager Spider-Man, the muscular Hulk, mutant outsiders The X-Men, the closest Fantastic Four and the playboy inventor Tony Stark, more famous as Iron Man.
Dozens of Marvel Comics films, with almost all of the lead roles Lee created, were produced during the first decades of the 21st century and amounted to over $ 20 billion in theaters worldwide, according to the cash office analyst.
Spider-Man is one of the most successful licensed characters ever and has risen through New York's skyline as a giant inflatable in Macy's Thanksgiving Day Parade.
Lee, like an employee handed to Marvel, received limited payback on the fall of his characters.
In a contract in 1998 he violated a 10 percent clause of profits from movies and television shows with Marvel characters. In 2002, he sued to claim his share, months after "Spider-Man" conquered cinemas. In a legal settlement three years later, he received a one-time payment of $ 10 million.
Hollywood studios made superheroes the foundation stone in their strategy of producing fewer movies and relying on huge gains from blockbusters. Some people assumed that, as a result, Lee's wealth had risen. He disputed it.
"I do not have $ 200 million. I do not have $ 150 million. I do not have 100 million dollars or anywhere near it," Lee said to the Playboy magazine in 2014. After growing up in the big depression, Lee added he was "happy enough to get a nice paycheck and be treated well."
In 2008, Lee National Medal of Arts was awarded the highest public award for creative artists.
Lee was born as Stanley Martin Lieber in New York on December 28, 1922, son of Jewish immigrants from Romania. At the age of 17, he became an older boy at the Timely Comics, the company that would develop into Marvel. He got the job using an inner connection, his uncle, according to Lee's autobiography "Excelsior!"
Lee soon earned written assignments and promotions. He wrote western stories and romances, as well as superhero stories, and often wrote on the porch on Long Island, New York, home he shared with his wife, actress Joan Lee, whom he married in 1947 and died in 2017.
The couple had two children, Joan Celia born 1950 and Jan Lee who died within three days of birth in 1953.
In 1961 Lee saw a rival publisher's success with caped crusaders and told Lee to dream of a superhero day.
Lee at that time felt series was a dead end career. But his wife urged him to give it a shot and create the complex characters he wanted, even if it led to his firing.
The result was Fantastic Four. It was stretchable Mr. Fantastic, his future wife Invisible Woman, her brother Human Torch and strongman The Thing. They were like a devoted but dysfunctional family.
"Stan characters were always superheroes who had a certain amount of humanity about them or an error," said Shirrel Rhoades, a former vice president of Marvel and its publisher in the mid 1990's.
"As iconic as Superman may be, he is considered a Boy Scout. He has no real shortcomings," said Rhoades. "While taking a Spider-Man, the children identify with him because he had his problems as they did. He suffered a lot of worry."
Lee involved his artists in the process of creating the story and the characters themselves, in what would be known as "Marvel Method". It sometimes led critics to wrong Lee to receive ideas that were not entirely personal.
He described his creative process for Reuters as he explained how he came up with his character, Thor, the thunderstorm borrowed from Norwegian mythology.
"I tried to think of something that would be completely different," he said. "What could be bigger and even more powerful than Hulk? And I thought why not a legendary god?"
To give Thor more rhetorical pause, Lee gave him the dialogue styled after the Bible and Shakespeare.
In the case of Tony Stark-Iron Man, he was based on industrialist Howard Hughes, Lee told interviewers.
Lee became Marvel's publisher in 1972. He went to the classroom, moved to Los Angeles in 1980 and sought opportunities for his characters in movies and television.
All in all, he kept in touch with the fans and wrote a column called "Stan's Soapbox", where he often forgot in his contractual phrase "Nuff Said" or the "Excelsior!" Signature. In his later years, he gave constant updates via Twitter.
"Stan was a character. He was a character as much as he ever created," said Rhoades. "He created himself in a way."
He also made cameos in most Marvel movies, pulling a girl away from falling litter in 2002's "Spider-Man" and served as a sleeve on a band club in the 2016's "Deadpool".
Walt Disney Co bought Marvel Entertainment 2009 for $ 4 billion in a store to expand Disney's roster of characters, with the most iconic that has been reading handcrafts.
By that time, Lee had all the extraordinary ways of Marvel after becoming a chairman emeritus at the company. But even in the 80's and 90's, Lee was a bunch of new projects, which ran a company called POW! Entertainment.
"His greatest legacy will not only be to create his characters but also how he helped build the culture that the series has become, which is quite big," says Robert Thompson, a pop culture expert at Syracuse University.