The Crucible

The Crucible is a brawling arena in the Braving Grounds District of Vasselheim, first appearing in. It fits the theme of the Braving Grounds, which are dedicated to Kord, a god of battle and competition, though the Crucible is a regular fighting pit and there is a separate, sacred arena for very special occasions.

The Crucible featured prominently in Vox Machina's early adventures in Vasselheim and introduced several recurring characters, including Kern "The Hammer", the Siren, and Earthbreaker Groon. Built for warriors to test their strength in competition, the crucible often attracts gamblers, including Vox Machina during Grog's fight against Kern.

Phillip vs. Kern
In, Grog (under the ring name "Phillip") fought a ferocious bout against Kern, the reigning champion of the arena. After a long and evenly matched battle, Grog appeared to have won, but Kern's half-orc endurance allowed him to come back for a finishing blow.

After losing his pride, and Vox Machina's gold, Grog prepared himself for a rematch.

Phillip vs. Kern, reprised
Grog returned to the Crucible and fought a furious rematch with Kern in the episode fittingly titled. This time, Grog benefitted from the help of Scanlan and a Potion of Stone Giant Strength. Even with such boons, the fight still proved difficult, as Kern's training endowed him with the multiclass abilities of a monk. Grog, barely remaining conscious thanks to his Relentless Rage, finally defeated Kern.

As the battle ended, it appeared that Grog had earned the approval or respect of a mysterious monk, Earthbreaker Groon. Kern later revealed in that he had trained with the Earthbreaker before his rematch with Grog.