With a shy smile, he often looks down as he speaks, while deflecting questions with self-deprecating jokes.
The 36-year-old comic's almost childlike behavior conceals his status as a Hollywood workaholic who's unwaveringly loyal to his friends.
"I was in his office 12 hours a day, and he was either working with me, or working on editing something else, or working on one of his other projects," said David Dorfman, screenwriter of "Anger Management," which co-stars Sandler and Jack Nicholson. "He worked nonstop."
Sandler has used his clout not only to gain greater control over his own films, but also to boost the careers of former "Saturday Night Live" friends such as Rob Schneider, David Spade and Dana Carvey by guiding their pet projects through the studio system.
Dorfman described Sandler as "a benevolent mogul," and Carvey said his 2002 film, "The Master of Disguise," would have gone nowhere without Sandler's help.
"I mean, I owe him. I don't really know why he did it, you'd have to ask him. But it was great to have him push it through. I guess I was nice to him on `Saturday Night Live,"' Carvey said, adding with a laugh: "Thank God."
But some Sandler favors backfire. He gave directing duties of "The Master of Disguise" to his longtime production designer Perry Andelin Blake, although Blake had no previous experience. Critics complained that the film was a mess, and Sony was still reworking the movie shortly before its release last summer.
Carvey had already starred on the late-night comedy show for five years when Sandler began appearing in 1991, the same year as Spade, whose 2001 film, "Joe Dirt," and upcoming "Dickie Roberts: Former Child Star" were produced by Sandler.
During his five-year run on the show, Sandler was known for impish characters such as Canteen Boy and musical bits such as Operaman. "SNL" was also the launching pad for his enduring holiday hit "The Chanukah Song," a comical compendium of Jewish celebrities.
Before that, Sandler had worked mainly as a standup comedian, getting laughs with his jittery delivery. That's where friends say he developed his regular-guy charm.
"He's genuinely nervous on stage, and that's become part of his persona," Schneider said. "He's genuinely nervous up there, and then it's a surprise that he's funny and you become relaxed."
Sandler had small roles in 1993's "Coneheads" and the 1994 comedies "Mixed Nuts" and "Airheads" before getting his first starring role in 1995's "Billy Madison," about a lazy 20-something who goes back to elementary school so he can inherit his rich father's business.
The low-budget film grossed $25 million, and Sandler followed it the next year with "Happy Gilmore," about a golf prodigy with a violent temper. That film, which featured a memorable fist fight between Sandler's character and "The Price Is Right" host Bob Barker, collected $38 million.
While critics consistently trashed his work, Sandler's fan base grew with hits such as 1998's "The Wedding Singer," which earned $80 million, followed by "The Waterboy" and "Big Daddy," which each collected more than $160 million. That gave Sandler the freedom to do as he pleased, and he chose to give a helping hand to Schneider, whose career had been reduced to a few supporting roles in some of Sandler's films. "Deuce Bigalow: Male Gigolo," which Schneider co-wrote and starred in as a hapless male escort, became a $65 million hit for Sandler's production company, Happy Madison.
Although Sandler's 2000 comedy "Little Nicky" was a step backward from his recent blockbuster hits — underperforming with a $39 million gross — he still persuaded Sony Pictures to gamble on a cartoon partially inspired by a line in "The Chanukah Song."
The studio had avoided getting into the costly and risky business of animation, but studio boss Amy Pascal agreed to make 2002's "Eight Crazy Nights" after hearing a personal pitch from Sandler. Dorfman joked that the studio probably would have made "a Kabuki play" if Sandler had wanted. "If nothing else they respect box office," he said.
But the cartoon gamble didn't pay off as Sandler had hoped; "Eight Crazy Nights" earned only $24 million.
Sandler also spent some of his influence to get Sony's support for last year's "Punch-Drunk Love," an arty, esoteric comedy-drama about a repressed man who falls in love despite his horrible bouts of rage.
The movie earned only about $18 million, but friends said the film's somber elements attracted a highbrow audience that had previously sneered at Sandler.
"It's in a more acceptable form where critics can appreciate him, finally," Schneider said. "These people were six months ago (saying,) `moron,' `idiot,' `idiot savant,' at best."
When film critic Roger Ebert, who had despised all of Sandler's previous films, crossed paths with the comic at a party, he praised him for "Punch-Drunk Love." "I will have to tell my parents, so they can watch your show again," Sandler reportedly responded. "They had to stop watching your show because it made them say bad words."
Harsh critics are one reason he refuses to do print interviews.
"I think he figures, `Why support that?"' Schneider said.
Sandler still does TV interviews, but prefers to answer with jokes.
Asked by Associated Press Television News about why he wanted to work with three-time Oscar winner Nicholson in "Anger Management," he responded: "I said to myself, `This poor fellow needs a gig."'
He joked that his reason for devoting so much time to producing was: "Control. Not trusting anyone else. Fear of people. I don't like to be touched. As a producer I can guarantee that none of that stuff will happen."
Asked again why he devotes so much effort to producing, he shrugged. "I have no idea. I just started since `Billy Madison' getting involved in the whole process. The next thing you know I said, `Hey, gimme one of those credits that you guys always seem to take and you don't do nothin'."
The comedian has an intensely personal relationship with his co-workers, and Carvey described Sandler's Happy Madison production company as a "big family." The comic's Web site features him and co-workers playing basketball and romping on the company's new motor cart.
From composer to editor to production designer, Sandler prefers to work with the same people again and again while surrounding himself with buddies — even on-screen.
A few longtime friends regularly play goofy character roles in his films, and occasionally even his fiancee, Jackie Titone, turns up in a bit part, playing a waitress in "Big Daddy" and an angel in "Little Nicky."
"Almost everybody he works with, he's had a relationship with since college or at least for many, many years," Dorfman said. "He likes to work with his friends."