From left, Kevin Hart, Dwayne Johnson, Karen Gillan and Jack Black star in “Jumanji: Welcome to the Jungle.” (Frank Masi/Sony Pictures Entertainment) )

Twenty-two years later — and many leaps forward in video game and movie technology — comes a sequel to “Jumanji.”

“Jumanji: Welcome to the Jungle,” a souped-up follow-up to the 1995 film starring Robin Williams, also shares as its source the surreal 1981 picture book by writer and illustrator Chris Van Allsburg, about siblings who open a board game that brings jungle animals careering through their house.

The new film, directed by Jake Kasdan, is a genuine hoot and doesn’t take itself too seriously. It is smarter and more humorous than the first movie, and its digital effects — which include stampeding albino rhinos and mountain-scraping aerobatics — are far snazzier, as one would expect. It also delivers a message, geared to teens, about overcoming their insecurities to participate fully in life, without pounding the lesson into the ground.

The film’s stars — Dwayne Johnson, Jack Black, Kevin Hart and Karen Gillan — are darn near impossible to dislike, in roles that require them to play teenagers trapped in adult bodies. Some explanation is necessary.

In a prologue set in 1996, an abandoned copy of the Jumanji game from the first film is found on a beach. A teen rejects the old carved box, preferring his video game. But he hears the sound of drums coming from the box, opens it and —

Dwayne Johnson plays the video game avatar Dr. Smolder Bravestone in “Jumanji: Welcome to the Jungle.” (Frank Masi/Sony Pictures Entertainment) )

Cut to a present-day high school where four kids have landed in detention: neurotic nerd Spencer (Alex Wolff); hunky football jock Fridge (Ser’Darius Blain); shy brainiac Martha (Morgan Turner); and Instagram selfie queen Bethany (Madison Iseman). Left to tidy up a storage room as part of their punishment, the four discover the Jumanji box, inside which is an antique video game. The original board game, it seems, has evolved. The teens select avatars and accidentally, in a molecule-scrambling instant, beam themselves into the game’s jungle — not as themselves, but as their digital alter egos.

Spencer is now Dr. Smolder Bravestone (Johnson), a muscle-bound adventurer (though inside he’s still a worried kid). The handsome Fridge learns he is now Franklin “Moose” Finbar (Hart), a diminutive zoologist who whines a lot. Martha is now martial arts dynamo Ruby Roundhouse (Gillan).

Best of all, the self-absorbed Bethany has turned into Dr. Shelly Oberon, a paleontologist and cartographer played by Jack Black. That’s right. Shelly is short for Sheldon. In the film’s choicest moments, Black adopts subtle quirks of intonation and body language to channel a high school glamour girl who’s creeped out over having, as she puts it, “an overweight middle-aged man,” as her avatar. Black earns even more laughs when his character offers a seminar on flirting to the socially awkward Martha (a.k.a. Ruby) so she can distract a couple of bad guys while her cohorts execute a plan. The flirting tips also come in handy because she pines for the equally shy Spencer (a.k.a. Bravestone). Watching the imposing Johnson try to behave like an awkward teen has its rewards, too, though he’s not as inspired a comic actor as Black.

Karen Gillan plays the video game avatar Ruby Roundhouse in “Jumanji: Welcome to the Jungle.” (Photo by Frank Masi/Sony Pictures Entertainment) )

In the universe of the game, there is also a villain: greedy explorer Van Pelt (Bobby Cannavale), who has stolen a jewel from a sacred jaguar sculpture, bringing a curse upon the world of the game. To survive all its levels and exit Jumanji, the four avatars — with the help of a stranded pilot (Nick Jonas) — must dodge Van Pelt’s goons and return the jewel.

But it’s the characters, not the convoluted plot or digital magic, that make “Welcome to the Jungle” such fun. For a high-concept Hollywood special-effects movie, that’s quite a concept indeed.

PG-13. Opens December 20 at area theaters. Contains adventure action, suggestive material and some crude language. 118 minutes.