BOSTON — This city has a robust bar culture, with trivia nights, $1 oyster specials and plenty of other perks to keep patrons coming. But not since 1984, when “Cheers” was new to television, has Massachusetts allowed bars to hold happy hours.

It looked as if that might change last month, when the State Senate passed an amendment that could pave the way for bars and restaurants to once again serve free or discounted drinks during certain time periods.

The amendment’s ultimate passage seems doubtful now. But it has rekindled an old debate, even provoking a stern warning from former Gov. Michael Dukakis, who signed the ban on happy hours 27 years ago.

The Senate last month included the amendment in its version of a bill allowing casinos in Massachusetts. Specifically, it gave bars and restaurants the same rights that casinos would have under a new “gaming beverage license,” citing as theoretical examples “the right to give free alcoholic beverages to customers as part of promotions” and “drink specials that vary by night.”