We don't think about it all the time because most of the time it's easy to construct the sound of something from context. Sure, simply saying that your character sighs could mean any number of things, but contextually it's usually obvious whether it's meant as a gesture of exasperation or a sign of relaxed contentment. "Yes, I'm sure your new weapon will make a huge difference in the war" could be sarcastic or serious, but there are generally enough clues in the situation to make the difference obvious.
But there's one obvious case in which that breaks down, and that's in the matter of accents. After all, people from two different regions shouldn't quite sound the same... but there's also no effective way to communicate how one voice or another sounds different. And the most common solution is essentially a matter of making your character's words borderline unreadable in the hopes that you convey a sliver of your intention.
Now, it's obvious that for an awful lot of games, everyone of a given race does speak with the exact same accent. It makes sense that every Draenei in World of Warcraft would have roughly the same accent, since they're all from the same area and have the same cultural background. Then again, it makes less sense that every single human speaks with the same accent, as if the huge variety of human settlements of nations all coincidentally wound up with an identical accent to that used by residents of the northern United States. Logically, there should be more distinction.
But this isn't even a matter of verisimilitude. This is more often a matter of someone's trying to convey a character's speech through the most clumsy mechanism of all: phonetic spellings. You know, the sort of thing that dots comics, when you know a character is from the southern United States because he says "Ah ain't shuh 'bout all this commoshun, bawees."
If you had to read some of that sentence a second time to figure out what it said, you've identified the core problem. We don't write phonetically; we write for shared understanding. This column is equally legibile if you assume I'm from Boston or San Francisco or New Orleans. Pronounciation might differ a little, but the words are spelled the same way.
Phonetically typing out an accent works for a little while, but that's mostly because there are certain "accepted" misspellings for a given accent. Replacing the letter "w" with the letter "v," typing out the long "i" sound, clipping the "g" off of words like, well, "clipping." It relies on the other person's expectation that your mangled not-quite-English is meant to represent something agreed upon by shared cultural values.
But it still doesn't work, partly because these phonetics usually have an enormous breadth of application. "I vant an anzher" could be read as a variety of different European accents, even disregarding the number of different intonations it could have. The way I read it could be completely different from the way you read it.
Not to mention that you'd be devoting a lot of effort to associate your character with a gimmick rather than a character trait. Developing a character voice is tricky, but making your character's speech harder to understand at a glance isn't a step toward that voice. Unless your character is meant to be difficult to understand, there's no real advantage to trying to use a phonetic accent.
You're much better off focusing on dialect rather than accent because that you can weave in without trouble.
Let's use that example from before. Shucks, has to be some way you can make it clear your character has a drawl, you know? Surely can't come down just to misspellings. Reckon you can create the right tone just by word choice.
Don't focus on how the character sounds; focus on how the character speaks. If the character in question is supposed to have a heavy accent, he's more likely to use simple words and drop pronouns as well as pepper his speech with questions about how to express a complex thought. Careful use of elaborate words and measured diction project an air of class and sophistication. Certain dialects tend toward different sentence construction, and some words just don't crop up in certain areas.
The usual rejoinder is to point out that well, everyone knows how certain groups sound. Dwarves, for instance, are nearly universally Scottish in their accents. Everyone knows what they sound like, so there's no chance of someone misunderstanding the accent, right?
Except if everyone knows what a dwarf sounds like, why are you typing it out?
It really doesn't take any feats of mental gymnastics to assume that your character sounds similar to other characters from the same region. Typing it out is just one more way of making your dialogue more difficult to read while offering no additional insight into your character. It'd be one thing if you were actively trying to make a character hard to understand, but if it's just done on the premise of "well, he must sound like this," then you're throwing good effort after bad.
I understand the sentiments here, really. But your focus should be on what your character says and how he or she says it, not whether or not certain words sound different than you might expect. Make the character memorable, and then worry about any vocal quirks.
Feedback can be left in the comments below or sent along via email to firstname.lastname@example.org, just as with every other column. Next week, I'm going to explore a column tackled by a recent Daily Grind: Should roleplaying servers be policed? Should they exist if they won't be?
Every Friday, Eliot Lefebvre fills a column up with excellent advice on investing money, writing award-winning novels, and being elected to public office. Then he removes all of that, and you're left with Storyboard, which focuses on roleplaying in MMOs. It won't help you get elected, but it will help you pretend you did.