Wizards
In the game world of wizards, there are two significant additions--wild magic and elementalists. Wild magic is a strange, new type of magical power, just being explored and discovered for the first time. Wild mages are rare and exotic. Long before encountering such a wizard, characters may hear tell of a new type of magic in reports from travelers to distant lands. Of course, every adventurer knows that these reports tend to be exaggerated--more fiction than fact.
The first appearance of a wild mage is best presented by the DM as a mysterious NPC. The wild mage may join the party briefly or may be the springboard for an adventure. He should not be a henchman or hireling, but someone who is the characters' equal or superior. This gives players the opportunity to experience the wonders (and terrors) of wild magic before immersing themselves in this new art. After the characters have learned something of this strange magic, wild mage player characters may be introduced, perhaps as apprentices of the same NPC. Gradually, these new mages will become accepted members of the campaign world.
Elementalists can be introduced in a similar fashion, although their arrival is likely to be less mysterious. The first appearance of the specialization could be a small school or guild in a nearby town, established by an elementalist from distant lands (where such magic is common). The newly established wizard is likely to be looking for an apprentice; new characters are eligible to join the school. Of course, established mages may take an interest (both positive and negative) in his activities.
(See also Wizard, Player’s Handbook)