While their parents are out for the day with plans to bring some guests home from the opera, Judy and Peter Shepherd, after playing with some toys, become bored and decide to go to the park. There, they find a safari-themed board game called Jumanji. Taking the game home, they find a warning message: "VERY IMPORTANT. ONCE A GAME OF JUMANJI HAS STARTED, IT WILL NOT BE OVER UNTIL ONE PLAYER REACHES THE GOLDEN CITY." Ignoring the warning, they start to play.
The pair soon discovers that any dangers encountered in the game spring to life somewhere in the house. When Peter rolls a seven and lands on a space that says "Lion attacks, move back two spaces", an actual lion appears. Judy and Peter are able to trap it in the bedroom. They reluctantly continue the game as nobody will believe them that a lion appeared in their house.
Judy then rolls an eight and lands on a space that says "Monkeys steal food, miss one turn". This causes some monkeys to appear and cause a mess in the kitchen.
Peter then rolls and lands on a space that says "Monsoon season begins, miss one turn". This causes a monsoon to happen in their house where the lightning frightens the monkeys out of the kitchen.
Judy rolls the dice and lands on a space that says "Guide gets lost, lose a turn". The rain stops and Judy and Peter find a guide hunched over with a map trying to get his bearings. Judy and Peter are unable to get his attention.
Peter then rolls a six and lands on a space that says "Bitten by tsetse fly, contract sleeping sickness, lose a turn". A tsetse fly then appears. Peter tries to swat it away only to contract the sleeping sickness.
After being unable to wake Peter up, Judy rolls the dice and lands on a space that says "Rhinoceros stampede, go back two spaces". This causes a rhinoceros stampede to occur in their house as the rhinoceros herd runs through the living room and the dining room. It is enough to wake Peter up as he and Judy cover their ears to block out the noise of the breaking items.
Peter then rolls the dice and lands on a space that says "Python sneaks into camp, go back one space". An 8 ft. python then appears on top of the fireplace as it starts to wrap around the mantle of the clock. Looking up from his map, the guide moves to the far corner of the room and sits down on the couch with the monkeys.
After Judy lands on a blank space, Peter rolls a three and lands on a space that says "Volcano erupts, go back three spaces". The room begins to get warm and shakes a little. Molten lava then comes out of the fireplace and hits the monsoon waters causing the room to be filled with steam.