Originally Posted by
noob
2e and 1e are not so far from 3e and 5e in terms of classes but multiclassing worked very differently(there was dual classing and some other form of multiclassing and classes and multiclassings allowed depends on the race) so if 3e/5e characters were multiclassed it could make the conversion to earlier editions painfully complex to do.(and it is odd to see your dwarf something suddenly lose a bunch of levels "because they were above the class level cap for a dwarf" but that is kind of excepted when changing editions)