angharad_gam

Is why, in RPGs, you can usually only wear two magic rings at the same time. I wear eight rings as a matter of course, and could wear more, except I have never found any small enough to fit my pinky fingers (leaving aside plastic kiddie rings). And that's without getting into the mediaeval practice of wearing rings on the first finger joint as well as on the knuckle. Why would an adventurer not want to maximise their advantage by piling on as many magic rings as possible? A couple of reasons spring to mind:

Wearing rings that do not fit you very well (as would likely be the case if you had a random collection looted from various dubious sources) could make it more difficult to use a weapon properly. Speaking from experience, if a ring is too loose it pinches quite a bit if you try to get a firm grip on something, especially something hard. Still, this shouldn't stop mages or maybe even archers.
Magical interference. You might think the ring of attack and the ring of defense, and the ring of charisma, and the ring of perspicacity will work exactly as advertised, but when you put them on together what actually happens is that you turn an unpleasant shade of green and become highly attractive to termites.

Of course, the real reason is that it's just a pain to keep track of...