First of all, I’d like to say I think Jess addressed the basic issues of mechanics vs. concept very well, and I don’t have a whole of extra commentary to add to it. When it’s all said and done, John Jess is absolutely right. If your concept ties in nicely to the best leveling specialisatiion, or best raid specialisatiion, then you’re very lucky. More commonly, there’s a conflict, and when that happens, you have to make the call to say which is more important to you: Being true to your concept, or being true to your character?
However, I would add two points. The first is minor, but worth making: You can level with pretty much any talent specialisatiion. Seriously, you can. Holy Priest with no shadow spells whatsoever? Get a good wand, hammer down with those shields and your DoT, and make stick to one enemy at a time. It’s absolutely doable. It’s harder, I agree, but you can do it and you can do it at a decent clip. While it’s still a trade-off, I think at the leveling stage, the trade-off favors concept.
Raiding is another story. You’re being depended on by a number of other people, and if you do break with a classic specialisation, or refuse to learn spells, then you ought to let your raiding buddies know this before you go into a dungeon, and if they decide they’d rather go with a priest who can Mind Control, then you should take that gracefully. Like it or not, nobody else is forced to go along with your story.
My second point is the more complex one, however. In a nutshell, it goes like this: Sometimes your concept requires that you do things against your concept, at least temporarily.
The most obvious example I can think of here is the Grizzled Old Soldier archetype that I put forward in Do It Different: Paladins. This archetype just does not work well at lower levels – How can you have fought in three wars and only be level five? If you’re going to do this concept, there’s a lot of argument to be made for going retribution (or arms if you decided to do this as a warrior) and leveling up with as little role-playing as you can do until you hit, say, level sixty. Then respec to whichever specialisation you think best fits your concept, and find a good role-play guild. Consider this your point of starting play.
Aha, I hear you say. (I have pre-cognitive telepathy, I can actually hear your thoughts in response to this article before it’s even published.) But what about if you wanted to play the Old Priest? This time, you can’t just learn the Shadow spells to level up quick, and then dump them. Once a spell is learned, it’s learned forever! Well, true. You have to make the call, in the end, and decide if you’re prepared to try a long slog of a levelling process with no role-play until you’re ready to take on the character; to just grab the shadow spells and then deny having them later on, or (for a really radical option) leveling up as a concept more friendly to role-play at lower levels, then use a Paid Name Change and ditching all your friends once you hit a high enough level. (I don’t recommend this last one.) Sometimes, yeah, it’s an absolute trade-off and this is one example of it.
As we constantly lament, World of Warcraft is not the ideal format for role-play, and the mechanics aren’t set up to mesh well with role-play. Yet we continue to role-play there because we enjoy the setting, because it’s convenient, because we like getting our chocolate in your peanut butter. The two play elements of role-play and mechanics clash against each other; interact in odd ways. Learning to deal with those clashes is part of being a good role-player.