Metacritic reviews

A spirited, smart-alecky look at the ongoing conflict between a government that wants to eliminate pot and a public that wants to smoke it.

This turns out to be an informative, involving, even sobering advocacy film.

A flashy, smoker-friendly documentary on the twisted history of the evil weed -- and the misguided drug war against marijuana.

He's (Mann) a solid historian and this film is full of fascinating facts, but he's a cultural critic at heart, and a good one at that.

It's as entertaining and informative as anything Mann's ever done, and as good an example of grass humor as you're likely to find anywhere.

Charged with raucous energy and a satirical slant, this witty history lesson is preaching to the converted, sharing a knowing wink with everyone who's ever inhaled.

Until something better comes along, we're just gonna have to keep the fires burning on this Ron Mann Joint.

Grass's relentless hard sell ultimately grows wearisome. Although only 80 minutes, it ends, and not a moment too soon, with a pot legalization rally that might well be reproduced outside the theater.

Rich with statistics and snazzy visuals, but it ignores those larger questions and, as a result, feels a tad naïve.

It has as much of an ax to grind as the humorless and misguided bureaucrats it mocks.