[12] Affleck's first starring film role was as an aimless art student in the college drama Glory Daze (1995), with Stephen Holden of The New York Times remarking that his "affably mopey performance finds just the right balance between obnoxious and sad sack".

[51] When Affleck starred as a recently returned Korean War veteran in the coming-of-age drama Going All the Way (1997), Todd McCarthy of Variety found him "excellent",[52] while Janet Maslin of The New York Times noted that his "flair for comic self-doubt made a strong impression.

[11] The two friends moved back to Boston for a year before the film finally went into production, directed by Gus Van Sant, and co-starring Damon, Affleck, Minnie Driver, and Robin Williams.

[54] On its release, Janet Maslin of The New York Times praised the "smart and touching screenplay",[58] while Emanuel Levy of Variety found it "funny, nonchalant, moving and angry".

[59] Jay Carr of The Boston Globe wrote that Affleck brought "a beautifully nuanced tenderness" to his role as the working-class friend of Damon's mathematical prodigy character.

Janet Maslin of The New York Times remarked that the pair, playing fallen angels, "bring great, understandable enthusiasm to Mr. Smith's smart talk and wild imaginings".

[68] Affleck starred opposite Sandra Bullock in the romantic comedy Forces of Nature (1999), playing a groom whose attempts to get to his wedding are complicated by his free-spirited traveling companion.

"[72] He starred opposite Charlize Theron as a hardened criminal, with Elvis Mitchell of The New York Times enjoying the unexpected casting choice: "Affleck often suggests one of the Kennedys playing Clark Kent ...

Stephen Holden of The New York Times praised the "understated intensity and exquisite detail" of his performance: "His portrait of a young, sarcastically self-defined 'people person' who isn't half as confident as he would like to appear is close to definitive.

[79] Affleck then parodied Good Will Hunting with Damon and Van Sant in Kevin Smith's Jay and Silent Bob Strike Back (2001),[80] made a cameo in the comedy Daddy and Them (2001),[81] and had a supporting role in the little-seen The Third Wheel (2002).

[90] Caryn James of The New York Times praised the show's "nerve, imagination and clever writing",[91] but Robert Bianco of USA Today described it as a "knock-off" of Twin Peaks.

The film was almost uniformly panned,[100][101] with Manohla Dargis of the Los Angeles Times remarking that "Affleck doesn't have the chops or the charm to maneuver around (or past) bad material.

[116][117] In 2007, Affleck made his feature film directorial debut with Gone Baby Gone, a crime drama set in a working-class Boston neighborhood, starring his brother Casey as a private investigator searching for a young abductee.

[120] Manohla Dargis of The New York Times praised the film's "sensitivity to real struggle",[121] while Stephen Farber of The Hollywood Reporter described it as "thoughtful, deeply poignant, [and] splendidly executed".

Wesley Morris of The Boston Globe found him "very good in the film's silliest role,"[126] but David Edelstein of New York Magazine remarked of Affleck: "He might be smart and thoughtful in life [but] as an actor his wheels turn too slowly.

"[151] David Edelstein of New York Magazine noted that Fincher's controlled style of directing had a "remarkable" effect on Affleck's acting: "I never thought I'd write these words, but he carries the movie.

"[152] Justin Chang of Variety found Affleck "perfectly cast": "It's a tricky turn, requiring a measure of careful underplaying and emotional aloofness, and he nails it completely.

Andrew Barker of Variety found him "a winningly cranky, charismatic presence,"[157] while Brian Truitt of USA Today enjoyed his "strong" and "surprisingly emotional" take on the character.

[160] Peter Debruge of Variety felt Affleck's "boy-next-door" demeanor – "so normal and non-actorly that most of his performances feel like watching one of your buddies up on screen" – was "a terrific fit" for the role.

[168] Snyder stepped down during filming due to the death of his daughter,[169] the replacement director Joss Whedon's treatment of actors was the subject of complaints,[170] and Affleck himself was struggling with addiction issues.

[188] Richard Lawson of Vanity Fair said it was hard to avoid the movie's "meta angle": "Affleck handles his self-conscious task with a generous humility—giving a performance built not out of histrionics or big actor moments, but instead from the messy details of a man in a plateaued distress".

[194] He played Peter II, Count of Alençon, a hedonistic aristocrat in Ridley Scott's medieval drama The Last Duel; he also co-wrote the movie's screenplay with Damon and Nicole Holofcener.

[195][196] Bilge Ebiri of New York Magazine was impressed by Affleck's "imperious" performance as the "wonderfully skeezy Pierre, a marvelously out-there creation who shouldn't work at all and yet becomes an engine of uneasy delights.

"[201] Kevin Maher of The Times said he played the role with "extraordinary subtly and depth": "He dominates his every scene, with deftly delivered quips, comedy reaction shots or sheer hang-dog charisma alone.

"[207] Adam Nayman of The Ringer said the film "serves as an example of his formidable skill set within a very specific range": "What used to seem like the callow cockiness of a handsome front-runner has hardened—and deepened—into a kind of grizzled charisma, the gravitas of a frat boy facing down his own expiration date.

[211] Affleck portrayed the supporting role of Phil Knight, while other cast members include Matt Damon, Viola Davis, Chris Tucker, and Jason Bateman.

[260] Also that year, he and Howard Graham Buffett co-wrote an article for The Huffington Post, highlighting the "growing percentage of the food insecure population that is not eligible for federal nutrition programs".

[302][303] Affleck took part in a voter registration public service announcement,[304] and traveled with Kerry during the opening weekend of his Believe in America Tour, making speeches at rallies in Pennsylvania, West Virginia, and Ohio.

[363] In 2013, Affleck and Garner hosted an event for lawmakers at their home in support of a bill that would protect celebrities' children from harassment by photographers; their six-year-old daughter made a speech about her personal experiences.

[429] In 2014, Affleck was asked to refrain from playing blackjack at the Hard Rock Hotel in Las Vegas, after a series of wins aroused suspicion that he was counting cards, which is a legal gambling strategy, though frowned upon by casinos.