At the stroke of midnight on Oct. 17, Canada became only the second country in the world to legalize recreational marijuana. Canadian law now allows people 18 and older to buy pot, though some provinces have upped the minimum age to 19 to match the drinking age. Quebec’s new government has vowed to raise it further, to 21.

The end of marijuana prohibition is a watershed moment for Canada, but it comes with a lot of questions about how this will actually play out across the country. It also raises questions for Americans interested in partaking in the celebrations. So, before you hitch a ride to the border, here are three things you need to know:

THERE ARE STILL RULES

Canada is now the world’s largest legal weed marketplace, but this is not a pot free-for-all. You must follow local laws.

The new federal law sets a 30-gram – roughly 1 ounce – limit on how much marijuana people can buy or possess in public, but provincial or city governments may have other rules on where you can consume it. (Here, for instance, are the city of Calgary’s rules.) There is no current law on how much you can have at home, but there are limits on how much you can grow.

At present, the legal sale of pot is limited to fresh buds, oil, plants and seeds. Other products that are popular in some U.S. states – edibles, for instance – are not available for legal purchase yet across the border, though you can cook and consume them in someone’s home, according to Canada’s Global News.

Driving under the influence of drugs is still 100 percent illegal. This Montreal blog has a province-by-province list of penalties, but the bottom line is this: If you’re in Canada and you’re driving while high, you are breaking the law.

DON’T BRING POT BACK TO THE STATES

You cannot bring weed legally purchased in Canada back into the United States. Though several border states have legalized marijuana (or allow the use of medical marijuana), the border between Canada and the United States is, as my colleagues put it, “a thin marijuana militarized zone, where the drug will remain forbidden by federal law.”

Americans who buy legal weed and try to bring it back across the border risk arrest on possession or drug smuggling charges. And with Attorney General Jeff Sessions vowing to crack down on marijuana, that looks unlikely to change anytime soon.

“I think we’re going to have a rough year-and-a-half learning curve as far as the cross-border issues,” said Rino Bortolin, a city councilor in the border city of Windsor, Ontario, to The Washington Post.

HOW TO ROLL A JOINT

If you’re still craving a trip north, Canada’s newspaper of record, the Globe and Mail, is here for you. The paper published a completely earnest infographic on how to roll a joint, titled “I just bought cannabis. What do I do with it?”

If you succeed at your task, the paper has got a city-by-city lineup of munchies, too.