Actually in response to vikingeek, the rule of thumb is that dialog should be doing more than one thing at once. If it’s only furthering the plot of the story, you can use exposition or action to do that, same thing with characterization, the character’s clothes, mannerisms or actions can characterize a character. (How useless/boring is it to have dialog that just says: “oh that’s Marcy coming through the door”).
Also, all dialog should be characterizing the character anyway, so if the dialog is revealing something new about how the character is feeling/thinking/their personality, is furthering the plot/conflict, and/or doing more (revealing something about the setting/history/past, etc), it’s doing a good job. It’s something, I think, can only be done in revision (or with practice). Basically, I try to edit or cut any dialog that doesn’t fulfill this rule. That said, another rule of thumb is to not have the characters explicitly say what they’re thinking or feeling. Once you get good at implying it through subtext, things start to get interesting. Burroway’s Writing Fiction is really helpful when it comes to learning craft. Also, reading fiction in which dialog is well done (like Oscar Wilde’s Picture of Dorian Gray for example)—or plays, I love reading plays for this reason, because you can see all the different things a line of dialog is doing at once. Sorry, I just graduated with a Creative Writing degree at SFSU, so I’m very pumped about this stuff!
YW/Livia says: I just graduated from UNC-Chapel Hill with an English/Creative Writing degree, so I’m right there with you!!
And yes, when I said that dialogue has to further the plot or characterize, I didn’t mean that those two things were mutually exclusive. Think, for example, about a character exposing an important secret through dialogue: The secret can further the plot if it exposes something important, and the fact that the speaker is sharing a secret shows something about his or her moral character.
I love what you say about the characters not being explicit in their dialogue. Not that dialogue is supposed to mimic real-world conversation, but when you think about it, how many of us really are saying what we mean all the time? That tip is definitely going to stick with me. So thank you!
I have to disagree about the dialogue in Picture of Dorian Gray, though. I felt like it went on and on and on and Wilde just uses the dialogue as a platform on which to spew his worldview. I haven’t read it in a while though.