Jumanji is back.

The first trailer for the upcoming sequel “Jumanji: Welcome to the Jungle” debuted on Thursday, showing stars Dwayne Johnson and Kevin Hart in action.

The movie follows four high schoolers who discover an old video game and get sucked into its jungle setting. They take on the avatars of Johnson, Hart, Jack Black, and Karen Gillan, and must play against type (the meek Spencer becomes Johnson’s muscle-bound explorer Dr. Smolder Bravestone, while it-girl Bethany becomes Black’s Professor Shelly Oberon) to escape the jungle and return to the real world — before they’re stuck in the game forever.

The trailer shows each character getting acquainted with their new bodies. “Why am I wearing half a shirt and short shorts in the jungle?” Gillan asks. Black looks at his reflection and shrieks, “I’m an overweight middle-aged man.”

The original “Jumanji,” starring the late Robin Williams, did big business for Sony’s TriStar Pictures in 1995, grossing $262 million worldwide. That movie found two children playing the Jumanji board game, unwittingly releasing Williams’ Alan Parrish, who had been trapped in the game for years.

Ser’Darius Blain, Nick Jonas, Alex Wolff, Madison Iseman, and Morgan Turner also star in the film. Jake Kasdan (“Bad Teacher,” “Sex Tape”) is directing from a script by Chris McKenna, Erik Sommers, Scott Rosenberg, and Jeff Pinkner.

William Teitler and Matt Tolmach serve as executive producers; Kasdan, David Householter, Dany Garcia, Johnson, Mike Weber, and Ted Field are executive producing. Sony Pictures will release “Jumanji: Welcome to the Jungle” on Dec. 20.

Watch the trailer below: