The public gathering at the downtown Seattle Center, like a smaller turnout at a nearby spot hours earlier, defied a key provision of the state's landmark marijuana law, which allows possession of small amounts of cannabis but forbids users from lighting up outside the privacy of their homes.

Police kept their distance from both gatherings, underscoring mixed law enforcement messages about the new statute, known by its ballot designation as Initiative 502. The measure took effect on Thursday.

Seattle's city attorney issued a stern warning on Wednesday that public pot puffing would not be tolerated and that violators faced citations with $100 fines.

But the Seattle Police Department said its officers had been directed to limit any enforcement actions related to Initiative 502 to verbal warnings only, at least for now.

The new law, passed by voters last month in a move that could set the state up for a showdown with the federal government, removes criminal sanctions for anyone 21 or older possessing 1 ounce (28.5 grams) or less of pot for personal use.

Colorado voters likewise chose to legalize pot for personal recreational use, but that measure is not due to take effect until next month. Both states are among 18 that have already removed criminal sanctions for medical use of marijuana.

The Washington law also legalizes possession of up to 16 ounces (0.45 kg) of solid cannabis-infused goods - such as brownies - and up to 72 ounces (2.4 kg) of weed in liquid form.

But driving under the influence of cannabis or imbibing in public places where the consumption of alcohol is already banned remain illegal.

NO SELLING OR SHARING ALLOWED

The new law ultimately will permit cannabis to be legally sold and taxed at state-licensed stores in a system to be modeled after those in many states for alcohol sales. The state Liquor Control Board, along with agriculture and public health officials, have until next December to set up such a system.

For now, it remains a crime to sell, cultivate or even share one's own stash, even though the law allows individuals to purchase a limited amount for personal possession.

Ironically, the first known court challenge of the law came from a medical marijuana patient in Olympia, who filed suit last week seeking to block enforcement of a new standard for marijuana impairment while driving, similar to the blood-alcohol standard for drunken driving.

The plaintiff, Arthur West, says the new legal limit - 5 nanograms per milliliter of blood of THC, pot's active ingredient - would unfairly subject him to prosecution for a THC level at which he routinely drives without impairment. A hearing on his request for an injunction was set for Friday.

Little if any of the law's fine points seemed to matter to the mellow group of about 300 people - from college-age tokers to middle-aged Baby Boomers - who assembled at the Seattle Center fountain, a short distance from the Space Needle.

Convivial laughter, laid-back conversation and occasional coughing filled the air as the pungent smell of marijuana wafted through the crowd, many wearing sweatshirt hoodies to ward off the chill, on a cold, crisp evening.

'SAFER THAN ALCOHOL'

Carrying a sign, "marijuana is safer than alcohol," Jared Allaway, 30, described the night as "iconic."

"Seattle's always been friendly to cannabis," Allaway said. "Hopefully this will spread to eastern Washington. You get outside of Seattle, it's a different world."

Seated in a wheelchair that sported a "Goddess" sticker, medical marijuana patient Penny Simons, 52, said she traveled with friends from Renton, Washington, south of Seattle, to attend the smoke-in.

"It's history," she said. "I've been thinking about the people across the country who are jailed for this. It's nice to see things change."

A smaller crowd of about 100 pot-smoking celebrants had assembled about 19 hours earlier nearby for a count-down to the law taking effect at the stroke of midnight, blaring the music of reggae legend Bob Marley from loudspeakers.

Both gatherings were peaceful, with no reports of arrests.

(Additional reporting by Jonathan Kaminsky in Olympia; Writing by Steve Gorman; Editing by Cynthia Johnston, Todd Eastham, Peter Cooney and Lisa Shumaker)

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