Canada is about to do something very few countries in the world have tried: make recreational pot legal.

Today, Prime Minister Justin Trudeau's government will reveal precisely what it thinks legalization should look like, and there are a ton of fascinating and important questions that need to be answered.

First, let's start with what we already know.

CBC News has reported that the federal government will set a minimum age of 18 to buy marijuana, but will give provinces and territories the option to set the age higher. Where it will be sold and how much it will cost will also be up to the provinces to decide. The federal government will license producers and ensure the safety of the supply.

CBC News has also reported that the personal possession limit will be 30 grams. Households will be allowed to grow up to four plants. There will be restrictions around how cannabis products are marketed and the government will use roadside saliva tests to determine if drivers are impaired.

According to CBC News sources, the goal is to make legalization a reality across the country before July 1, 2018.

But before that happens there are still lots of questions to answer.

Will there be a 'sin tax?'

Taxing pot is a big deal for a couple of reasons. On the one hand, a "sin" or excise tax could mean more revenue for the government, which Trudeau has suggested be funnelled back into addiction services and public education. But charge too much, and you wind up with a problem.

As the parliamentary budget watchdog pointed out in its analysis of the fiscal considerations when legalizing pot, if tax is too high, buyers will stick with the black market. The PBO analysis points out that when Colorado legalized pot in 2014, it charged a combined tax rate of nearly 30 per cent. About half of consumers stayed in the illegal market.

And if there is a sin tax, how might it be applied? That same PBO report notes that one option would be to apply it by weight or even based on potency (i.e. THC levels).

What about chocolate bars and gummy bears?

This isn't just a cute question. There are potentially serious public health implications. The chair of the government's cannabis task force, Anne McLellan, said that her group learned some important lessons about edibles from Colorado's experience.

She said at first the state didn't require chocolate bars containing marijuana to be scored into individual pieces. Some people would eat the whole bar in one sitting and wind up in the emergency room, McLellan said.

The concerns are even more serious when it comes to children, who could mistake some edibles, like gummy bears and lollipops, for candy. Children's Hospital Colorado has a warning on its website that the drug can have a stronger and more prolonged effect on kids. Many require hospitalizations.

The federal task force recommended the government ban any cannabis products that could be "appealing to children," based on the products themselves or their packaging.

Where can you smoke it?

What sort of restrictions will the government put in place around where marijuana can be consumed? Should it be subject to the same restrictions as cigarettes? Or perhaps alcohol?

The task force recommended that the restrictions around tobacco products should be extended to cannabis, and that jurisdictions should have Ottawa's blessing to set up cannabis lounges and tasting rooms.

What counts as stoned?

Police enforcement against drugged driving will be tricky. The federal government has been running pilot projects on different saliva tests that can be administered roadside to determine if a driver is under the influence. But the question is not entirely clear-cut.

"Whereas evidence was gathered over many years to arrive at an established metric for alcohol intoxication — blood alcohol concentration (BAC) — these types of data do not exist for cannabis," the cannabis task force report notes.

For some regular users, THC can remain in the brain and body for prolonged periods of time. But does that mean a driver is impaired?

The Liberals have promised harsher penalties for drug-impaired drivers.

"We are confident we will have an arrangement in place that will meet the public interest," Public Safety Minister Ralph Goodale told reporters in Ottawa earlier this week.

What about pot tourism?

Trudeau has said he is legalizing marijuana in order to keep it away from kids and to cut profits to organized crime, but obviously, legalizing pot will have plenty of other consequences.

What about Americans who want to come up for the weekend to check out Canada's beautiful wildlife and legalized marijuana?

The federal government may be happy to embrace the potential financial windfall that would come with marijuana tourism. Officials could also try to repress it (or cash in further), by charging an added tax to tourists.

The marijuana task force also recommended that tourists be informed of their rights and obligations, including not taking drugs across international borders.

Can it be done in time?

Quebec Premier Philippe Couillard said on Wednesday that proposing legislation is the easy part. The hard part, he said, is the work the provinces will still have to do — including on issues like distribution, marketing and road safety.

Couillard said expecting that work to be done by the summer of 2018 is "very fast" for such a complex subject.

Even medical marijuana companies that are anxious to start selling to recreation buyers aren't sure the system will be ready in time.

"I don't think anyone should be expecting to buy recreational marijuana on Day 1," at least by going into a federally sanctioned store front, said Sébastien St. Louis, co-founder of Hydropothecary, a Quebec-based licensed producer of medical marijuana.

"By the time we get around to knowing exactly how the provinces want to move forward it will probably take a bit longer than July 2018."

(For the sake of full disclosure, it's worth noting that one member of Hydropothecary's board has held leadership roles in the federal Liberal Party.)

Still, St. Louis said that even if the bricks and mortar facilities aren't ready, licensed producers will be ready to sell through a direct mail system right off the bat.