Massachusetts is now entering a legal gray zone, because retail stores selling marijuana won’t open until January 2018 at the earliest. Adults will be permitted to purchase, possess, home-grow, and use marijuana starting Thursday, but the people they are buying it from will be breaking the law by selling the drug. Only sales from the regulated market will be legal, and that market won’t open for at least a year.

Marijuana becomes legal in Massachusetts on Thursday for adults 21 and older. But if you want to purchase some pot, you’re going to need to do it the old-fashioned way: from a guy who knows a guy.


The awkward situation was set up intentionally by the authors of the law, who say it was essential to end prohibition of the drug as soon as possible and give regulators enough time to set up proper oversight for the nascent industry. But the drafters acknowledge the dueling imperatives create an imperfect gap year.

“People who want to use marijuana are going to have to get it from the same sources they were getting it from before Dec. 15,” said Jim Borghesani, one of the leaders of the successful referendum effort. “The gray zone is not ideal, but there’s really no other way around it.”

Borghesani said keeping that period as short as possible is one of the reasons lawmakers, who are thinking about delaying when stores can open, should leave the referendum unchanged.

Despite legalization, selling marijuana in Massachusetts outside of the regulated market will remain a crime punishable by up to two years of incarceration and up to a $5,000 fine.

Colorado faced a similar, awkward transition period. Voters there legalized recreational marijuana in November 2012, but retail marijuana stores did not open until January 2014.

Chief John Jackson of the Greenwood Village, Colo., Police Department said the best words for that period were “disconcerting and confusing. It puts your law enforcement in this gray area with no clear guidance on what to do.”


And John Suthers, the attorney general of Colorado during the gray zone for that state, offered a more stark warning for Massachusetts: “It will be a mess for law enforcement.”

Suthers, a strong opponent of marijuana legalization efforts, said Massachusetts should expect a huge increase in black market activity as people ramp up home-growing operations to supply new consumers.

“People will grow it in their homes. They’ll sell it. That kind of small operation has never been a priority for law enforcement anyway,” Suthers said. “It certainly won’t be now.”

The new Massachusetts law will allow for home-growing up to six plants per person, with a maximum of 12 per household.

“The nightmare for you is going to be the unenforceability of the limitation on 12 plants per house,’’ Suthers predicted. “And the danger is in this year’s period of time, a significant black market will arise that will be in competition with the stores when they come online.”

But Mason Tvert, a top national legalization proponent with the Marijuana Policy Project, said the fears of a huge new black market are simply not rooted in reality.

“It didn’t happen in Colorado, it didn’t in Washington, it didn’t in Alaska, it didn’t in Oregon,” he said, listing four legalization states.

He called the concern “the new version of reefer madness.”


Local Massachusetts law enforcement officials are beginning to grapple with the complexity of the strange new world that dawns Thursday.

Daniel Bennett, the state’s public safety secretary, is circulating a memo for law enforcement. His spokesman, Felix Browne, said the document outlines how the new law will change the way police carry out their duties, “and offers detailed guidance on issues affecting public safety in areas such as operating under the influence, the abuse and neglect of children, and offenses involving unlicensed distribution and trafficking of marijuana outside the regulated market that will be permitted under the new law.”

Jeremy Warnick, a spokesman for the Cambridge Police Department, said the city would enforce the laws on the books, but acknowledged the gray zone “does make it challenging.”

He said officers will receive an in-depth briefing on marijuana statutes with a city lawyer in coming weeks.

Lieutenant Detective Mike McCarthy of the Boston Police Department emphasized selling marijuana will remain illegal.

“You cannot sell. So if you’re violating the law and you’re caught, you may be prosecuted,” he said.

The law, which is poised to be formally certified by the Governor’s Council Wednesday, does offer users other ways to procure marijuana.

Adam Fine, a Boston-based lawyer who was involved in drafting the ballot measure and is part of a high-powered firm that focuses on marijuana issues, pointed to part of the law that will allow giving away up to an ounce of marijuana without remuneration, as long as the transfer is not advertised publicly.


He said that language is meant to ensure a marijuana “social scene” is legal, just as it is with alcohol, and people can “share some small amounts of marijuana with friends in the privacy of their own home without being seen as drug dealers.”

So can residents throw a pot party Thursday night and offer guests joints and bong rips, just as they might offer them glasses of wine and tequila shots?

That will be legal under state law, Fine said, as long as guests are not paying cash or its equivalent for the marijuana.

But it’s important to note, he said, that the host of such a party could face civil liability for a guest who causes injury or property damage as a result of being under the influence of marijuana or alcohol.

And tokers can’t take pot parties to the street: Consuming marijuana in public will remain illegal, as will smoking weed anywhere where tobacco smoking is prohibited.

Another quandary: The law allows for home-growing starting Thursday. But, before retail stores open, it does not address how people can purchase goods to start a cannabis garden.

Transferring seeds or seedlings without remuneration will not be against the law. But selling marijuana outside the regulated market — even if it’s a live plant instead of the dry, smokable plant matter — will remain illegal.

“Very few plants are started from seeds, most plants are started from clones,” said pro-legalization lawyer Michael D. Cutler, referring to cuttings from a mature cannabis plant that are used to grow new ones. Starting Thursday, receiving clones is perfectly legal, but selling them for money still won’t be, he said.


Also illegal, Cutler said: medical marijuana patients transferring pot to other people.

To be sure, Massachusetts has been in a different version of a legal gray zone since 2008, when voters decriminalized marijuana, replacing the criminal penalties for possession of 1 ounce or less with a new system of civil penalties.

And then there’s the biggest legal gray zone of all. Even as voters in eight states and the District of Columbia have legalized the drug, marijuana remains strictly forbidden under federal law, classified in the same category as ecstasy, LSD, and heroin.

Many in the marijuana industry worry that the Trump administration will crack down on commercial pot operations, undoing what they see as years of progress.

Joshua Miller can be reached at joshua.miller@globe.com. Follow him on Twitter @jm_bos. Click here to subscribe to his weekday e-mail update on politics.