In 1996 in the small town of Brantford, New Hampshire, a teenager named Alex Vreeke (played by Mason Guccione and Colin Hanks) discovers a mysterious Jumanji board game, which was unearthed by his father on a beach. However, when Alex rejects the game, it magically morphs into a video game cartridge. Once he starts playing, he is instantly transported into the Jumanji game itself.
Fast forward twenty years to 2016, we meet four high school students from Brantford High who find themselves in detention: Spencer Gilpin (portrayed by Alex Wolff), who got caught writing essays for his former friend, Anthony "Fridge" Johnson (Ser'Darius Blain), and two girls, Bethany Walker (Madison Iseman) and Martha Kaply (Morgan Turner), who misbehaved in class and disrespected their teachers. To atone for their actions, they are instructed by Principal (Marc Evan Jackson) to clean out the school's basement. To their surprise, they stumble across the Jumanji video game, and after navigating through some controls, they inadvertently activate it—resulting in them being drawn into the game world.
In this vibrant jungle setting, each of them becomes their chosen game avatars. Spencer finds himself transformed into Dr. Smolder Bravestone (Dwayne Johnson), a dashing, muscular explorer endowed with incredible abilities and seemingly no weaknesses. Fridge, on the other hand, emerges as Franklin "Mouse" Finbar (Kevin Hart), a diminutive zoologist whose strengths lie in weaponry, despite his comical short stature and some unfortunate weaknesses, including a fondness for cake. Martha becomes Ruby Roundhouse (Karen Gillan), a skilled commando proficient in various martial arts, and the character Bethany finds herself as an unexpectedly portly Professor Sheldon "Shelly" Oberon (Jack Black), a knowledgeable cartographer with expertise in multiple fields.
As they quickly learn, they are indeed players in a video game, each possessing three lives that they must protect at all costs. A misstep leading to a loss of all lives results in their permanent demise. With help from an NPC guide named Nigel (Rhys Darby), they learn that they must reclaim a stolen gem known as the "Jaguar's Eye" from the infamous big-game hunter, Russel Van Pelt (Bobby Cannavale), who aims to control the game's creatures with its powers. To break free from Jumanji, the group must return the gem to an imposing jaguar statue and utter "Jumanji."
As the team embarks on their perilous journey, they face numerous challenges, losing lives in their bid to conquer game levels. Their connection strengthens when they narrowly evade capture thanks to Alex (Nick Jonas), the fifth player, who has been trapped in the game for two decades. Together, they rally to help him escape and navigate various dangers together. After commandeering a helicopter in a dramatic sequence, they reach the jaguar statue where Alex faces a writhing mosquito, leading to a life-threatening situation. In a heart-stopping moment, Bethany comes to the rescue, performing CPR and transferring her life to save him.
Upon arriving at the statue, the team confronts Van Pelt and his minions. They must rely on their wits and teamwork, launching a clever distraction to allow Spencer to successfully return the gem to the statue and call out Jumanji's name. With that, they finally break the game's hold, seeing Van Pelt transformed into a horde of rats as they emerge back into the real world. However, they soon realize that Alex is missing.
As they head home, they discover that Alex's former home—once in disrepair—has been beautifully restored. The adult Alex unexpectedly appears, revealing he was able to return to 1996, rewriting history. Grateful for the team’s intervention, he names his eldest daughter after Bethany. This shared journey forges a stronger bond among the teens: Spencer reconciles with Fridge, Bethany evolves into a more considerate individual and plans a future adventure, and Martha embarks on a romance with Spencer. Their group dynamic has transformed entirely, and they hear the ominous drumbeats of Jumanji in the distance. Determined to prevent anyone else from falling into the game's trap, they decide to destroy it for good using a bowling ball they found during detention.
