A few weeks ago I ended up joining my boyfriend's Dungeons and Dragons roleplaying group. I'm having a blast so far, but it's also a kind of strange experience for a WoW player, because WoW was my first roleplaying game of any kind, so going back to one of its "ancestors" is both weird and enlightening.
Take the soloing vs. grouping debate for example. I'm guessing that most WoW players, even the really social ones, spend a fair amount of time playing alone, exploring, doing quests and so on. Solo roleplaying on the other hand simply doesn't exist. I mean, your character might temporarily get separated from the group, go off on a short side quest or whatever, but as a rule of thumb being in a group and messing around with your friends is what it's all about. If you spend extended amounts of time making up solo adventures for your character you're basically acting as a storyteller, but you're not playing.
The obvious reason why that doesn't work in an MMO like WoW is that you're going to encounter a lot of strangers, with whom you won't interact nearly as cordially as you do with your friends, so it's a completely different environment to begin with. Still, it does make you wonder what a game like WoW would be like if your first priority after creating your character was not to level up, but to join a party and get acquainted.
Also, character life cycles. In WoW, it's all about levelling up as quickly as possible to hit the cap, which is where a lot of the action happens. Some people might prefer to level more slowly and to create lots of alts, but gaining levels is still a major focus of the game even then. Also, once you've created a character, you never lose it unless you delete it. Death in game really doesn't mean anything but a minor temporary stat penalty.
In pen and paper D&D there is no hard level cap (though I guess in practice you probably won't go far beyond twenty), and levelling is just something that kind of happens on the side as you adventure. You'll want to have a minimum amount of levels and skills before you confront the big bad of the campaign, but your dungeon master will generally adjust the monsters you meet in such a way to be challenging and interesting to fight for the party regardless of your level.
Dying is pretty final... there is a spell to resurrect the dead, but it's designed in such a way that it's rarely feasible to use. On the plus side, since you're almost always grouped, there should always be a helpful party member nearby who'll try to save you if you get into really grave danger, and the DM's encounter design should ensure that you don't end up throwing yourself against opponents against whom you don't stand a chance to begin with.
Still, there's a pretty good chance that you'll lose a few party members throughout the campaign, but players are generally pretty laid back about this, because while you lose your character, it doesn't mean that you're out of the game. Generally you can just roll up a new character to replace your old one, and it will automatically start at a high enough level to be able to join the adventuring party.
Also, regardless of whether your character survives the adventure or not, there will always be an end to the story, at which point you'll shelve your little adventurer and create a new one for the next campaign. It's like a never-ending cycle of alt creation.
Once again, imagining such a scenario in WoW is pretty mind-boggling. Perma-death? Oh noes! Then again, you'd also have the ability to roll up a character at a higher level. Unfortunately it's quite obvious why such a system wouldn't work in a game where gaining levels and hitting the cap is largely the point of the game.
Another thing that really threw me for a loop in my first D&D session was the length of combat. Just playing out an encounter with a couple of monsters takes absolutely ages, as you have to decide on character actions for each round of combat and roll half a dozen dice to determine the outcome. The funny thing is that all of this more or less exists in WoW as well, it's all just calculated so quickly in the background that you can kill most things in a matter of seconds and then go "now what".
To "make up" for this you have travel in WoW, as you actually have to physically move your character from one point to another yourself all the time, even if some of it is automated by flight paths and the like. Compared to that, moving anywhere in a D&D game is instant. Oh sure, getting to the next town might take a couple of days in-game time, but if nothing of relevance happens during that time the DM will just say so and you can immediately continue at the point where you've already arrived at your destination.
In this case I can't actually say that I clearly prefer one solution over the other. Overly drawn-out combat sequences can get boring, but since you have to look at every detail in the process it also gives you a certain appreciation for things like a massive blow just missing your character, or one of your allies pulling off a particularly impressive maneuver. WoW's fast combat is missing that, but on the other hand it means that you're left with more time to admire the scenery and do other things (even if I guess that many players don't actually appreciate that).
Finally, the last big difference that really stood out to me was in regards to items. My current D&D character has a cloak which gives her plus two to charisma. Looking at this from the point of view of someone who's used to WoW's endgame numbers that's pretty lame, right? To make things worse, you can't have two items that give you the same stat bonus, so I couldn't have boots of charisma as well. Thinking of the massive single-stat stacking that's going on in WoW, that just makes me laugh.
Nonetheless good items are still highly coveted. It's just all on a much smaller scale, so even a small plus to a single stat can make a lot of difference. What really differentiates it from WoW is that you won't actually change your gear all that much throughout the adventure. It takes a massive backseat to other kinds of development.
Looking at all these differences, you can't help but wonder how a game like WoW ever got to where it is now. Who said that there had to be a hard level cap? Why did reaching that become the main goal and why was so much more content placed there than anywhere else? It's funny how we take a lot of these things for granted and accept them as necessary without even thinking about it.