Eltab
Lord of the Hidden Layer
The limits can help provide flavor to THIS world, compared to all the others.  Consider Dark Sun vs Forgotten Realms.  
I would put limits on subclasses not whole classes ("Everybody knows that Gnomes are the only really good Illusion Wizards, but they are horrible Greatweapon Fighters; they can barely pick up a two-handed anything!").
Ideal candidate subclasses for racial limits would reference / enhance the racial abilities in some way: got Darkvision? then Night Ward Ranger is for you.
And if in print for public consumption, an obligatory short sidebar about "Ask your DM."
				
			I would put limits on subclasses not whole classes ("Everybody knows that Gnomes are the only really good Illusion Wizards, but they are horrible Greatweapon Fighters; they can barely pick up a two-handed anything!").
Ideal candidate subclasses for racial limits would reference / enhance the racial abilities in some way: got Darkvision? then Night Ward Ranger is for you.
And if in print for public consumption, an obligatory short sidebar about "Ask your DM."
 
				 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		