Dungeons & Dragons, Monsters & Treasure booklet (1974, Gary Gygax & Dave Arneson), page 33:

"A [magic] ring must be worn to be employed, and only one ring may be worn on each hand if the ring is to be operable by the wearer. (The referee should be careful to enforce this in order to maintain some balance in the game.)"

If you like glancing directly into the face of Cthulhu, FATAL may be the RPG system for you.

well I don't have any problem with the two ring rule, but I would like an option to have a box to equip the rings on your toes if your PC is cool and hip.

Because it's cartoon characters with only four fingers per hand?

In Skyrim (as always) we have a mod for that!

http://www.nexusmods.com/skyrim/mods/6703/?
which always begs the question about removing cursed rings...

I just remembered Torchlight allows for your pet to wear rings. Okay. :P

Try to get a cat to wear a ring.

For TL 2 they changed this to tags.

I would sure love if this were visualized realistically.
Well duh, they wear them as bracelets! Of course that implies that the pets in Torchlight are seriously undernourished but still, duh!

thats holy dude alright. I guess the restriction comes originally from the old D&D / AD&D - where this was explained in lines along "magical stuff doesnt work too close to each other" or something like that.

..personally that brings into my mind some anti-magic tricks the designers probably didnt think of, but never mind :)

Two Worlds allows you to wear four rings - but no amulet, if my memory is correct.

It's generally a game balance issue.

From a in-universe perspective, you can think of it as similar to electromagnetic interference. Powerful artifacts radiate energies that could negate each other's effects.

Oh fuck, that's funny. I didn't expect that... LOL I literaly blew a huge snot bubble and bust out laughing. Thanks for the laugh. :)
Perhaps they can add another game to this game series based on this video...
https://www.youtube.com/watch?v=8Uztj3vp-RI

A whole thread about wearing multiple rings... and not one other person so far has even mentioned The Mandarin?

Internets, you disappoint me yet again. :p

In Thunderscape, each of your party of six can wear up to six rings and an amulet.

In the Disgaea games (some? all?), you can equip one weapon and several of anything else. You can equip three pairs of boots if you want.

In Sword and Sorcery: Underworld, knights can equip two-handed weapons in one hand once they reach a certain level. What's funny is that it's bugged and lets you equip lots of weapons. I was able to equip at least three or four, I didn't try to see how high it would go.

I feel for your girlfriends (past, present and future) if you can even consider that as an idea let alone pull that off.


Edit:::
I think you can wear 2 rings on each hand in Dungeon Siege. I need to go back to that game at some point.