The idea of the main characters getting sucked into the game itself rather than staying in the real world is similar to the Jumanji animated series, which itself was an altered retelling of the first Jumanji movie.
Karen Gillan posted a photo of herself and her personal trainer Scott Pearlman whom helped her get into shape for the film on her official Instagram account on November 10th, 2016 and thanked Pearlman for whipping her into shape for the movie.
The 3rd adventure film set in the jungle to star Jack Black. Jack Black had starred in King Kong (2005) as the filmmaker Carl Denham, and Tropic Thunder (2008) playing an actor, Jeff Portnoy. In this film, he plays a virtual character.
It was speculated that the film would be about Dwayne Johnson, Karen Gillan, Kevin Hart and Jack Black's characters finding the board game and being sucked into the world of Jumanji and setting out to find a way of escaping back into the real world.
The cast members were asked if they were able to sing a part of Welcome To The Jungle. All members did. Jack Black sang lead vocals, then The Rock and Kevin Heart joined him. Jack Black decided to perform Axl Rose's (non-forgettable, iconic) scream.