Thats one of my main oppositions. Any class or multiclass stat requirement forces all characters through a cookie cutter. Those requirements should be taken as suggestions only.One problem I forgot to mention in my first post is that the ability requirements are based on a stereotypical and narrow-minded view of each class. Multiclass fighters have to have a Str of 15. But what if I want to play an archer fighter or a swashbuckler-like finesse fighter that prefers Dex over Str? Nope, you still need a 15 Str. WotC built fighters tough! Rawr!
As for my DMing, I did select "other requirement" - that being the class shifting must be roleplayed. I won't allow it for gamist purposes only, no matter what the stats are. This is a loose requirement, but it's there. Don't go thinking a 1st level spellbook will appear in your pack because, out of the blue, you took a level in mage, because you want invisibility two levels from now. That's fine, but let's see that character show interest prior to the class change or multi. If its to be a spontaneous change, lets work something out that makes sense to the character. That's all I ask -
ex. Mage practicing with sword despite the -6 , takes a warrior level
- halfling thief eats mushrooms, becomes druid
- druid hit by lightning, takes level in berserker
- fighter with interest in ancient languages takes lvl in mage
multiclassing is a rich opportunity for character development