A Very Harold & Kumar 3D Christmas

Like the holiday season or a pot brownie, “A Very Harold & Kumar 3D Christmas” takes a while to kick in, but once it does it’s cheerful, merry, and ultimately rather exhausting. And once a year feels like plenty.

The third entry in this absurdly raucous stoner franchise, again written by Jon Hurwitz and Hayden Schlossberg, finds once-inseparable pals Harold (John Cho) and Kumar (Kal Penn) separated. Harold has given up weed, taken a job on Wall Street, and moved into a comfortable suburban home with his wife, Maria (Paula Garces). Harold is happily domesticated now, with no place in his life for Kumar, who remains perpetually stoned, unambitious, and a magnet for trouble. When his ex-girlfriend, Vanessa (Danneel Harris), stops by with urgent news, it’s all Kumar can do to talk to her AND watch TV at the same time.

Circumstances reunite Harold and Kumar on Christmas Eve, and once again they are thrust into an improbable adventure that veers between hilarious and tiring: more tiring in the first half, hilarious in the second. They’re accompanied by the guys they’ve chosen as replacement friends. Harold has Todd (Tom Lennon), a dweeby house-husband with a man-crush on Harold, and Kumar has Adrian (Amir Blumenfeld), a horndog trying to score with a girl he met online. The four of them — plus Todd’s 2-year-old daughter — get involved in a quest to find a Christmas tree, which naturally leads to a run-in with a Russian mob boss (Elias Koteas), which inevitably leads to being mistaken for chorus members in a Christmas show at Radio City Music Hall, which predictably leads to a tripped-out hallucination sequence where everything is in Claymation. You know the routine!

It is something of a “routine” by now. This entry (directed by first-timer Todd Strauss-Schulson) improves on the road-trip shenanigans of “Harold & Kumar Escape from Guantanamo Bay” and is probably comparable with the original “Harold & Kumar Go to White Castle” — which is to say it’s sporadically hilarious but not consistently so. They’ve gone all out to incorporate Christmas into the story, adding sex ‘n’ drugs to holidays traditions both religious and secular — everything from “A Christmas Story” to Jesus — all as part of the series’ ongoing mission to be offensive to everyone and therefore not really offensive to anyone. The characters are still casually racist, so absurdly and in so many directions that there’s no reason not to laugh.

As usual, the high point is the arrival of Neil Patrick Harris, reprising his role as an obscene, drug-addled version of himself. There’s now an extra layer of comedy subtext when he riffs on his public image as a lovable, self-aware, multi-talented showman, because it’s his appearance in the first “Harold & Kumar” that helped establish that cultural cachet in the first place. Then he was joking about his descent into post-adolescent-fame oblivion; now he’s joking about how popular he is. One hesitates to say that NPH can do no wrong … but if he can, I haven’t seen him do it. In terms of delivery and timing, his work in this movie constitutes one of the sharpest comic performances of the year.

The rest of the supporting cast isn’t nearly as useful. Adding a secondary pair of hapless boobs merely takes time away from Harold and Kumar — who, truth be told, aren’t as much fun to be around this time. (Maybe it was a mistake to have them giving each other the cold shoulder for such a significant portion of the movie.) Everything involving Harold’s protective father-in-law (Danny Trejo) is disappointingly bland and sitcom-y, like it wandered in from a Tim Allen movie. On the other hand, there are inspiringly whacked-out ideas like the WaffleBot, a hot holiday gift item that factors bizarrely into the story. I remember the good parts of the movie more than the bad parts — which might be something else it has in common with the Christmas season.

B- (1 hr., 30 min.; R, abundant harsh profanity, a lot of nonsexual nudity, vulgar language and sexual dialogue, some violent images.)