[Labyrinth Lord] Easy Multiclassing

The only game I found which handled multiclassing in an elegant and simple way was D&D 3.X. And I had my gripes with that as well, the least being that it demanded a complete rewrite of the system and it’s classes to be feasible.
That was… a bit over the top I guess. But well, the game was a success, and despite the bloat rather playable.
It doesn’t work with the older editions though. In the older editions we have the awful concepts of dualclassing and multiclassing, which both kind of work, but are so artificial I wish they wouldn’t. So this is my way of fixing the whole mess for my games. It’s not an easy system for the characters. It punishes people for focussing too much on one career path, but that is actually quite ok I guess. The more someone advances in a class, the harder it is to learn something new. At a certain point it becomes more feasible to just start over again.
Requirements: this should work with race-as-class classes as well, but of course the requirement here is that the character has to be the actual race to take up a race class.

Divergent Classes
Characters can gain levels in up to 2 other classes after they already started a character if they 1) fulfill the requirements and 2) pay XP amounting to the highest level threshold among all the classes. So a character gaining a level in a new class will have to pay XP as if he was gaining a new level in his original class.
The characters uses the best abilities, saving throws, spells, and attack rolls available to him.
[yes, that means if a level 10 fighter wants a level of thief he has to pay 480,000 XP for each level of thief until both his careers are the same level]

Example: William the Wizard is a level 5 magic-user. He travels through the wastelands with his companions, fights quite a bit with strange creatures, and in the evening he lets Fred the Fighter teach him some martial arts. When the time comes to gain a new level William’s player decides that William might need some fighting prowess if he is to survive the wilderness. So he gains a level of Fighter. If he decides to level up his Fighter levels instead of his levels as Magic-User he will continue to pay XP as if he was levelling as a Magic-User, until the cost of the next level of Fighter is higher than that.

Synchronous Classes
Characters whose levels of classes are the same may level both classes together after gaining enough XP for both classes.

Example: William the Wizard is now a Fighter and a Magic-User of level 5. He decides that this is exactly what he is, a fighting mage, and decides to pursue this path of advancement. It’s harder for him now (he has to gain experience for both his careers) but the benefits are larger (he can roll twice for hit points after levelling).

Dual Classing
Characters can change careers and level in another class for the normal cost of advancement from level 1 on. For this the lose all the benefits gained by their previous class (including saving rolls, spells, and hitpoints), as they now focus exclusively on the new class. They gain the old abilities again after they reach the level of their previous class with their new class. After this they can level according to the above rules.

Example: Fred the Fighter learned a lot during his time teaching William. After teaching him a long time he gained some appreciation for the arcane arts. So much actually that he decides to learn magic for himself. When they reach the next city he searches out the local wizard and becomes his apprentice for a while. After a few months the wizard has taught him everything he could teach him, and Fred goes forth, searching for new opportunities to get better in his new craft.

Related articles

• Brewing Potions (untimately.blogspot.com)
• [Untimately] Theorems & Thaumaturgy (untimately.blogspot.com)