What's considered to be a good time/level to change your mage's class?
To quote from
an old post (slightly editied) of mine:
In general I recommend developing Sorcerers, Wizards and Archmages ASAP. Start with base Conjurer or Magician class, then change to Sorcerer at level 7/spell level 3, and if possible switch back to the other base class after having gained the Sorcerer and Wizard lvl 7 spells. Gaining levels in the base classes is much faster than for the advenced classes, and current class level determines initiative (I'm fairly certain) and saving throws.
There are some differences between the games; no Archmage class in BT1, for example, so this is general advice.
Recommende parties:
BT1-2:
Paladin
Monk Hunter (assuming the Critical Hit bug is fixed).
Bard
Conjurer
Magician
Conjurer/Magician
Turn one mage into Archmage (learn all the spells), one into master Sorceror ASAP and the third into master Wizard ASAP.
In BT1 have them all end their careers in the opposite base class of that which they started in.
In BT2 the Archmage is a class.
You don't really need a Rogue, since the Hunter is a better killer and mages can just cast the cheap TRAPZAP spell at no risk.
EDIT: Although the Rogue's ability to Hide and attack monster that are far away should be quite useful at times.