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