TORONTO -- It's an age-old pairing that's sparked a subgenre of films, shows and standup acts: cannabis and comedy.

"You just have to watch a Cheech and Chong movie to know that cannabis makes you susceptible to laughter," says Mark Breslin, founder of Yuk Yuk's comedy clubs in Canada.

Yet stoned audiences are often the toughest to make laugh, say standup comics, who note that what high crowds lack in audible appreciation they make up for in friendly feedback and less heckling than drinking audiences.

"They might not laugh at you the entire show but after they'll stop you outside and be like, 'Dude, that was the best show,"' says comic Mike Rita, host of the Stoner Sundays comedy showcase at Vapor Central in Toronto.

"I'm like, 'But you didn't laugh.' They're like: 'You don't have to laugh -- you've just got to feel it, man."'

Vapor Central is among several "4/20-friendly" Canadian comedy clubs that have been catering to medical marijuana users for several years now and are bracing for a possible influx of patrons or bylaw changes when Canada legalizes recreational cannabis use in October.

"It's one of the most forgiving audiences, just because they're down to have fun," says comedian Andrew Packer, who runs the Jokes N Tokes comedy showcase at the Underground Cafe and Social Club in Toronto, where cannabis use is allowed inside.

"You can feel how engaged they are. I don't want to sound too hippy dippy or whatever, but it's a vibe."

Toronto's Hotbox Lounge and Shop and the Green Leaf Vapour Lounge in Brampton, Ont., are among the other venues that host cannabis-friendly standup shows. There's also a Toronto Cannabis Comedy Festival planned for later this month.

Comedy producer Joanne Baker, who is a medical marijuana user, opened the Underground Cafe and Social Club in 2006. Comics who've performed there include Joe Rogan, Scott Thompson, DeAnne Smith, and Kenny Robinson.

"Not all comedians can cut it in the room," Baker says.

"It's like Andrew Dice Clay in a feminist crowd -- there are different kinds of comedy crowds, and cannabis comedy is very specific."

High comedy crowds tend to like political humour and often don't enjoy comedy that shames people, says Baker.

"Sometimes you'll say something self-deprecating and you'll hear someone in the room go, 'Aw, don't say that,"' she says.

Observational humour and nostalgia work well on a high crowd, notes Rita.

"I will bring up things like, 'What was your favourite childhood candy?' and I'll get a discussion in the room going for five minutes," he says.

Audiences at Baker's club also want to see diversity onstage.

"People get upset if it's all white people in the show," Baker says.

"So I have a mandate: pretty much all our shows have to have women on them and minorities."

Baker notes high comedy crowds are on a different mental level than those who are drinking and may seem more difficult because they're so inside their heads.

"A drunk person will laugh at everything, the drunker they are," Baker says.

"Sometimes (stoned) people are one step ahead of the comic, thinking about what they're saying as they're saying it, so you've got to be able to play with that."

That lack of explosive laughter in a high crowd can be tough on some comics, who may stay away from the "weed rooms" because they're afraid to bomb, says Rita.

"Bombing in a normal room, you still get these pity laughs. In a weed room, there are zero pity laughs," Rita adds.

"If you're crap, you're going to stand up there in silence -- and a really deep silence -- and the only thing helping you out is people coughing on bong hits."

But Rita embraces the challenge, noting it helps him be a better comic. You just have to be overly prepared before going onstage in front of a high crowd, he says.

Packer and Rita also say stoned audiences heckle less and deal better with silence during a show than sober or drunk ones.

"With people drinking, it invites them to yell out something in those pauses," Packer says.

"If they're stoned, they'll just zone out or just enjoy themselves regardless of the situation."

Yuk Yuk's founder Breslin says he isn't considering allowing cannabis use in his club come Oct. 17, but most comics he knows use marijuana and some have done so before going onstage at his club.

"In a lot of ways comedy and pot act in similar ways," Breslin says. "They both create analogical thought rather than A follows B follows C.

"The thought process for comedy and pot is: A follows B follows orange follows 4."

Even if comics don't use cannabis personally, they sometimes get a contact high anyway while onstage.

"The whole audience is facing you, so all their little mouths are breathing weed smoke towards you and you're just standing up there alone taking it all in," Rita says.

"I've seen comedians who don't smoke weed absolutely destroyed by the end of their set not knowing what's going on."