Sitxh level. It allows for characters to have many of the staple powers and spells, makes them hardy enough to survive intense combat, usualy allows them to take a level or two in a PRC, yet by that level they are still normal heroes - not superheroes and definitely ot gods. They are still killable (and don't have Raise Dead yet by themselves - though they probably have enought money and/or resources to arrange for an NPC to cast it); they don't have too many spells a day (though they have enought to make the game interesting); and the game mechanics are not overloaded yet by too much modifiers and options.