But times change. Tastes, too.

The closing of The Casablanca in Harvard Square last year is a case in point. For six decades, the colorful Brattle Street bistro was a gathering place for academics, artists, politicians, and visiting VIPs, who mixed spirited conversation with fine food and drink.

What made The Casablanca such a lively hangout spot was location, for one thing. Close to two major universities, it fed upon the vibrant scene in and around the Square, even as it enriched it. There was also a genial proprietor on site, a friendly and knowledgeable staff, and a convivial, late-night vibe that made regulars feel as if they belonged in the bar’s movie-themed wall murals, tipping one with Bogie.

A creature of its times (1950s and ’60s), The Casablanca was a throwback of sorts to the taverns that have been a fixture of urban life since Roman times. Part community center, part watering hole, these collegial establishments can be found from the British Isles to Australia to Canada. Walk into one a couple of times, and everybody indeed might know your name.

The enduring popularity of “Cheers” notwithstanding, many local establishments offer that intoxicating mix of conviviality, comfort food, and creative drinksmanship. On a recent weeknight, we dropped in on three places — in Copley Square, Downtown Crossing, and Kendall Square — each claiming its own distinctive clientele.

Oak Long Bar + Restaurant

Night after night, bartender Phil Richardson spies many of the same faces settling onto barstools at the Oak Long Bar + Restaurant, located in the Fairmont Copley Plaza hotel. He should. Richardson has been pouring drinks in downtown Boston for nearly 40 years. He began at the Marketplace Cafe in the 1970s, then moved to The Palm, where he stayed for 16 years. When the Oak reopened for business last summer, after an eight-month, multimillion-dollar makeover, Richardson signed on.

It didn’t take long for his regular customers to follow him. Richardson has a lot of Sam Malone in him, greeting patrons by name and inquiring about their busy lives while he goes about polishing and pouring. As much as anyone in town, Richardson knows which ingredients turn a pleasant place to enjoy a craft cocktail and tasty bar fare into a regular hangout. “It’s a warm greeting, it’s remembering someone’s name and what they drink,” Richardson explained while refreshing a glass for Jeff Carter, an Oak regular, who sat at one end of the coppertop bar.

Pointing to his own graying hair, Richardson joked, “Sometimes I’ll remember what they drink before I remember the name.”

According to Oak management, about 30 percent of the bar’s patrons are hotel guests. The rest are Back Bay residents and office workers looking for a place to unwind, one they can easily walk to (even in a snowstorm). The daytime crowd typically skews younger as the night wears on.

Carter, 41, who works in the Hancock Tower, comes here once a week or so, occasionally to meet office friends but more often by himself.

“Phil makes you feel like you’re a friend, like you’re important as opposed to being just another customer,” Carter said, sipping a beer. “To me, that’s what makes this a hangout spot.”

JM Curley

Downtown Crossing had few hangout spots before JM Curley opened in 2011. A novelty at first, it initially drew attention with its cheeky “Law & Order” rules (“Thou shalt not covet thy neighbor’s date...”), minimalist decor (bare brick walls, unpolished wooden floors), and simple yet imaginative food (designer burgers, pizzas), modestly priced. The newest addition is a back-room steakhouse called Bogie’s Place, which has its own tiny bar.

The Curley bar attracts chefs from around town. “It’s become very much an industry bar, for people who work in other bars and restaurants,” said Ethan Rush, enjoying a glass of Malbec on a chilly winter’s night. Although early, the barstools and tables were already packed with after-work drinkers and diners. Median age? Thirty-something.

Rush, 30, lives in Somerville and bartends at Les Zygomates, a South Street wine bar. He comes here once a week or so, often joined by workmates.