As part of an annual tradition, Bob and his close-knit group of friends participate in the Buddy Games, a series of exhilarating challenges aimed at building camaraderie and reinforcing their friendships. The current champion, Shelly, has dominated the events, boasting six victories, including a recent triumph in a paintball clash against Bender. Following the chaotic celebrations, Bender and Nikki, Shelly's wife, jokingly suggest that it's time for revenge, targeting Shelly's weakest point. However, it becomes clear that while Bender had initially intended to shoot Shelly, Nikki stepped in at the last moment, leading to a catastrophic incident where Shelly ends up losing both testicles—a secret he chooses to keep hidden from everyone.
Fast forward five years, and Shelly finds himself in a bleak state; his marriage to Nikki has crumbled, leaving him to navigate a life filled with despair. His concerned mother reaches out to Bob, now a prosperous entrepreneur, pleading with him to revive the Buddy Games to reignite Shelly's will to live. When Bob pitches the idea to Shelly, he agrees but lays down two strict conditions: no one can discover his condition, and Bender must be excluded from participating.
Bob reaches out to their friends, excluding Bender, and receives overwhelmingly positive responses. Unfortunately, Bob's girlfriend is less enthusiastic about his plans to join the Buddy Games again, resulting in a tense argument that ends with her storming off in a helicopter. Meanwhile, Bender learns about the resurrection of the Buddy Games from the grapevine and confronts Bob at his luxurious mansion. In an attempt to spare Bender's feelings about being left out, Bob fabricates a story, claiming that there’s a hefty $10,000 entry fee this year. He also shares the shocking news about Shelly's misfortune, hinting at a troubling shift in their relationships.
As the friends gather at the cabin, their reunion is interrupted by Bender's unexpected arrival. Desperate for inclusion, he discloses that he has sold his deceased mother's belongings and performed dubious services to gain entry. This revelation casts a somber mood among the group as Bender reveals Shelly's traumatic loss, prompting Bob to finally admit the truth about the invitation issue. With tensions bubbling under the surface, Bender challenges Bob to put up a significant cash prize for the winner, appealing to the financial struggles each friend is experiencing, particularly Shelly, who longs for parenthood. Reluctantly, Shelly agrees to let Bender join the competition.
The first day kicks off with a thrilling lineup of events, starting with a fierce eating contest, followed by exciting mini motorcycle races, a wild water slide adventure, a treacherous muddy obstacle course, and a chaotic watermelon smashing event. Bob emerges victorious in the opening event due to Shelly's failure to signal at the finish line after the water slide. The next challenge takes a daring turn, demanding the friends to down an entire bottle of laxatives before trying to flirt at a bar. Bender claims victory with cunning tactics. As the games continue, the group engages in a surreal contest where they find themselves with raw steaks on their heads, only to be confronted by a komodo dragon, leading to an intense battle of wits and survival as they try to outlast the beast. Remarkably, Shelly comes out on top, although he appears mentally compromised after biting the dragon's tongue.
The final trio of Bob, Shelly, and Bender makes their way to the last leg of the competition. The night before the finale, they celebrate with piña coladas, oblivious to Shelly's devious act of secretly spiking their drinks with Bender's sperm. Amid their laughter at a commercial featuring Durfy, the mockery intensifies Durfy's frustration, leading him into the woods, where he suffers a savage attack by a rabid animal. Bob and the others, worried for Durfy, find him and convince him to perform spontaneously, breathing new life into his flagging acting career.
Chaos unfolds in the cabin when Bender's much-needed rest is abruptly interrupted by Shelly, who takes advantage of the situation by binding Bender to a tree with duct tape. The next morning, Shelly escalates his vendetta by deliberately causing damage to Bender’s sentimental van— a symbol of his late mother's affection and his personal turmoil. However, Bender has a bombshell of his own: it was Nikki who pulled the trigger that led to his tragic loss.
The climactic day of the competition arrives, where the two remaining contenders, Shelly and Bender, don protective gear and engage in a wild cat-and-mouse chase across an open field. Bob's girlfriend, Tiffany, attempts to intervene but her efforts are cut short when Bob is knocked out of the competition. As the epic struggle continues, Shelly initially gains the upper hand, but Bender displays incredible reflexes by snatching an arrow in motion. Their contest escalates into a fierce hand-to-hand combat, ultimately concluding with Bender claiming victory and the cash prize.
Tiffany later proposes to Bob, receiving a firm rejection that triggers a fiery confrontation, resulting in her unleashing a torrent of pent-up emotions on Bob and his friends.
As the credits roll, a touching scene unfolds where Zane reveals his true colors to Doc, and Durfy secures a role on a hit CW show. However, Shelly continues to create distance from Bender, only for Bender to retaliate by abducting her, unveiling that he has purchased artificial scrotums with part of his winnings—a bizarre yet fitting development in their ongoing rivalry.
