Trial of the Grasses
Death or mutation. There is no middle ground for the boy who enters Kaer Morhen.
Few rites in history rival the Trial of the Grasses for sheer cruelty. Hidden within the stone walls of Kaer Morhen, this alchemical ritual forces young initiates to ingest a volatile cocktail of mutagens that rewrites their very biology. It is less a test than a biological lottery: failure brings excruciating agony or death, while success births a being with reflexes and senses beyond human limits.
- Location
- Kaer Morhen
- Purpose
- Witcher Mutation & Selection Process
- Survival Rate
- Extremely Low (Historically)
- Key Figures
- Alchemists, Witchers, Young Initiates
- Primary Outcome
- Creation of a Mutated Witcher or Death
Lore & Background
Beyond the shattered bones and fevered delirium lies a deeper cost: the erasure of the self. Alchemists at Kaer Morhen view initiates not as children, but as raw material to be refined. Survivors emerge severed from humanity—too mutated for villages, too human for monsters. This isolation is the true mutation; the silver eyes and slow aging are merely symptoms of a soul forged in fire.
In Their Own Story
The air in the chamber was thick with the scent of crushed herbs and copper blood. Little Geralt lay strapped to a stone table, his small chest heaving as the alchemists poured the green sludge into his throat. It tasted of ash and rotting earth. Then came the fire. It did not burn from the outside but erupted within every vein, turning his bones to glass and his blood to lava. He screamed until his voice broke, his vision blurring between the dark stone ceiling and hallucinations of writhing shadows. Time lost all meaning as his heart hammered against ribs that felt like they were shattering and reforming in the same instant. In the darkness behind his eyelids, he saw a wolf howling at a moon that wasn't there. When the fever finally broke and the silence returned, he opened his eyes to find them glowing with an unnatural, feline luminescence. He was alive, but the boy who had entered the room was gone.
Reader's Guide
Survival is only the first step. Those who endure the Grasses face the Additional Trials, a series of further potion infusions designed to push mutated physiology beyond its breaking point. Most who pass the initial Trial perish here. The few who survive gain immunity to poison and disease, but their bodies remain in perpetual flux, requiring constant maintenance through specific potions and training.
Did You Know?
- Historically, only about three out of ten boys survived the initial Trial of the Grasses before any additional mutations were attempted.
- The mutation process is what gives witchers their characteristic cat-like eyes and the ability to see in total darkness.
- In some lore iterations, the Trial was so dangerous that it led to the decline of certain witcher schools due to a lack of survivors.
- Geralt of Rivia survived not only the standard Grasses but also additional experimental mutations that killed most other candidates.