Ath'kethin
Elder Thing
Something we've done is to make the various wizard specialists actual specialists - that is, only a Diviner can cast Divination spells, only an Illusionist can cast Illusion spells, etc.honestly magic needs to get more grounded as it is just all over the place and overrule every other part of the game.
it needs limits.
It keeps wizards form being a one-size-fits-all solution, since choosing a specialization actually specializes (i.e. limits) them.
It also means that the types of wizards we see is directly related to the type of campaign we are running; very few Diviners in a combat-heavy game, very few Evokers in a combat-light game, etc. There's been some grumbling, but most have enjoyed the variety and challenge.