[MENTION=6777693]transtemporal[/MENTION] #64
Cheese is never really ok at my table, and my personal preference is single class for a reason:
One of the Basics of fantasy rpg often overseen today is that you got a bunch of PCs who complement each other in their strengths and weaknesses
On Multiclass: If it is justified by RP it is more believable , if it occurs. Some class combos in my point of view are extremely contradictive and unbelievable e.g.
Paladin / rogue for moral and code of honor reasons, any Combo of fighter and other fighter types e.g. ranger/monk fighter/barbarian paladin/barbarian etc.
these only make sense if you want a cheesy power build. In some editions a fallen paladin reverts to fighter (in some Editions a fallen ranger also) but that is rather like losing some of your class powers than gaining something by multiclassing.
"Multiclassing" i liked was e.g. the basic editions elf class, you can easily emulate that class by elfs being eldritch knights.
That also applies to several other things which required multiclass before 5E:
E.G.
Take the criminal Background and you got basically a rogue multiclass for free.
So you got your choice of arcane trickster e.g. or wizard with criminal background.
And that is ok and sufficient, you do not need a thief wizard multiclass instead.
Your arcane trickster will backstab and hide .
Your criminal wizard is a bit better at casting and that's it.
He is still e.g. the groups best caster (fulfilling my balanced strengths and weaknesses theorem from above)
whereas being symmetric thief / mage he would be mediocre in both classes and lag behind single classes.