[Drajor]

There is many ways to approach this. Without fully exploring it here is roughly what my first attempt would be.
- Add an extra field to character_ or other table that has an association with a character. Call it class2.
- When a character reaches max level, give them a choice of next classes, store this in class2.
- Modify combat/spell code to handle things differently depending on class2.
- Spell/Disc learning would most likely need to be handled via server/script and would again look at class2.
- Equipment will be the hardest to do well. But again there are heaps of options. You could add a new field to the items table to constrain items to certain class2 types. The client will not know about this data so it will allow players to equip things that do no belong to the class. However, on the server you can look at how stats/bonuses are calculated from a characters inventory and put class2 checks in there. Another way would be to hijack the diety system and use that to both constrain the client and make bonus calculation easier on the server side. (There may also be a way with required skill on items .. I don't know much about this yet).

More knowledgeable folk then me may know more elegant approaches as well.