Spencer hides the pieces of the Jumanji video game, repairs the gaming system in his basement and gets sucked into the universe. Spencer's friends Bethany, Fridge, and Martha arrive to see Spencer missing along with the game being open and decide to re-enter Jumanji to save him. They witness the unexpected changes and move through the terrains of the most dangerous game in the world.

A crypto-zoological agency faces off against the god-sized monsters, including the mighty Godzilla who collides with his ultimate nemesis , King Ghidorah.