The thread on chat > general about strong multiclassed 'überpeds' got me thinking. Obviously, this will raise lots of angry objections, but it seems clear to me that HZ's unlimited multiclassing is creating an unbearable strain on the game.
The ramifications of extreme multiclassing are obvious. It creates hybrids that have no weaknesses, that feel unchallenged and ultimately, bored. They are of not one class but an amalgam of everything that is inheritable in their collection of trophies. This blurs the meaning of pure adventure schools and renders them meaningless.
There are two inbuilt restraints already in the system, which unfortunately have proven woefully inadequate.
Firstly, there is the inheritance of abilities at half the achieved level in the school. This somewhat limits the gathering of super-abilities to the lower half of the collected classes. (However, some of the low-level skills are extremely powerful in their own right; multicast being one of the primary 'offenders'. But i digress) This limit is, as it is now, a good start. The next step would be to limit the inheritance of both statistics and skill to no more than 75% of their achieved effectiveness. A statistic or skill built up to 1000 in one class would inherit as 750 to other classes.
Secondly, we have the class-defining skills that are not inheritable ('cannot be mastered'). The amount of uninheritable abilities needs to be increased drastically, both to cut down the accumulated strength of an 'überped' and to better define pure classes. Inherited abilities should not be inherited as-is, especially across the major divisions of melee-ranged-mystic-arcane. Their recycle timers going up a certain percentage would be one remedy. This would increase the importance of classes that straddle these divisional borders; battlemage (melee-arcane), paladin (melee-mystic) and elemental archer (ranged-arcane) for example.
Next, I would propose locking down the character's 'primary class'. This is the first class where he/she achieves level 21, changeable afterwards only by questing. When playing in this primary class, the above inheritance rules apply. When playing outside this primary class, even a stricter set of inheritance rules would be applied. Certain skills would 'inherit to primary class only', rendering them unusable when not playing in primary class.
Hybrids that approach rating 200 should be made redundant: first through a extremely daunting task of adding enough lateral content so a player would never feel the need to grind their 10th class to 100 - because there is nothing else to do. Second, by balancing the above restrictions so a pure classes would still compare favorably to a hybrid. It is a well-known fact that it is not so much about attributes or skills as abilities, so their masterability should come under especially close scrutiny. At the same time, classes in dire need of powering up or even finishing *cough*conjurer*cough* would be brought up to par.
It is possible that hitting all of these restrictions on multiclassing might in fact choke it too much. It is a common strategy in negotiations for both sides to pull into extremes so the middle ground lands into palatable position. This is one such extreme, from which one can step downwards to achieve a more moderate, and hopefully efficient, solution.