Class change requirements
For a character to change class, they must be level 20 or higher. Classes can only be changed at the Temple of Dharma. A character can change to any other class aside from the Hero class. However, in order to become a Sage, the character must either be a Goof-off, or possess a Book of Satori.
The hero class in Dragon Quest III is unique. The Hero of Dragon Quest III is not permitted to change classes and no other character may assume the hero class.
Class change mechanics
When changing classes, the character goes back to level 1 regardless of their current level or any previous level held while being another class. All of the characters statistics are reduced by half. Any spells learned are retained in the new class. A character may only equip items which are eligible to their class. No equipment can be carried over when changing classes.