Season 1: The Floor of Tests

Twenty-Fifth Bam enters the Tower chasing Rachel, passes Headon's first test, and on the Floor of Tests forms his first team with Khun and Rak while competing against other Regulars to prove he can climb.

Season 1, the foundational arc of Tower of God, introduces the central premise that drives the entire webtoon: a colossal, mysterious Tower whose floors are guarded by deadly tests, and a boy who climbs it for a single reason. Twenty-Fifth Bam has spent his entire life trapped beneath the Tower with only Rachel for company. When Rachel enters the Tower, Bam, an extraordinary being known as an Irregular, forces open the door himself and is greeted by the caretaker Headon, who declares him special. To follow her, Bam must climb, and the climb begins immediately with a brutal first test on the bottom floor. Reaching the Floor of Tests, Bam is thrown among dozens of other newcomer Regulars, all competing for the right to ascend. Here the series establishes its core social engine: progress depends not only on personal power but on forming teams, reading other climbers, and surviving administrator-designed trials. Bam meets Khun Aguero Agnes, a sharp strategist from one of the Tower's great families, and Rak Wraithraiser, a proud spear-bearing warrior. The three form the central trio whose bond anchors the rest of the story. They face a sequence of escalating tests, from the position-selection exams to the climactic Crown Game, where teams fight to hold a throne. The Crown Game becomes the emotional and structural turning point of the season. Bam's latent affinity for shinsu, the mysterious life-energy of the Tower, manifests violently for the first time when the guide Hwa Ryun attacks, revealing that Bam is no ordinary Regular. The season also introduces rivals and allies who recur for years: the Jahad Princesses Endorsi and Anak, the fire-user Yeon Yihwa, and test administrators like Lero-Ro and Yu Han Sung who quietly observe Bam's anomalous power. Season 1 closes on the devastating revelation that defines the entire series: Rachel, the friend Bam has risked everything to follow, betrays him out of jealousy and pushes him into a Shinsu sea, seemingly to his death. This betrayal recontextualizes the innocent climbing-adventure tone into a darker story of ambition, loss and identity, setting up Bam's transformation and the far larger conflicts of the seasons that follow.