Exactly how much information should I give out. Should I take the time to explain what's the Assembly, or why magical runes were outlawed 13 years ago? Sometimes I feel like,"Hey! You never explained what's the Assembly!" and sometimes I feel like,"Who cares what's the Assembly? It's not here right now. Get on with the story!" and sometimes, rarely, I feel like,"This is the perfect balance." So how do I get readers to feel the "perfect balance" fairly consistently?
I use my wikki characters to explain things. Have you ever watched NCIS ? It has two eccentric characters whose main function is to provide information, they are created in a way it is fun and interesting and actually they do infodump. In my first book I have two The Abbot and Gilbert who is the king's valet. They are the ones who provide my characters with the information when they need it. They are two of my favourite characters to write.
You don't need a detailed explanation to satisfy the reader. Something like "The assembly is where the guilds and noblemen of the city meet to discuss" (or whatever it is) will be enough for the the reader to begin with. There. One sentence. Its history, its internal power struggles, its relations to other organisation, etc, can be saved for when it's needed for the plot. EDIT: I also have kind of an infodump character... One of my characters soaks up knowledge like a sponge, and can provide facts about most things he and his friends encounter.
In my current book, I have a book that serves as an info dump. A character lose's his memory and another gives him the book, to re-learn the world. So as he progress' though his book, so is the reader reading the book. Maybe this thread should be relabeled to 'Info dump charaters' XD
Well, the info-dump is to be avoided at all costs in all sizes, flavors, and colors. I think the real question that needs asking is: What is the difference between info-dumping and exposition?
Only share information that is required to move the story forward, or which is essential to a character's development. If you spend my time telling me what the Assembly is, then it better have something to do with the plot. otherwise it's just filler. When you do tell me, make it interesting. Do it through conversation, or through action (As they strode through the hall of the Great Assembly, Skarvgaard and Twilly were filled with a sense of wonder. This is where the Old Ones set the Wheel in motion, Twilly thought. And where Gavlund fell, ending the Days of Light.)
QFT This is a very good example of exposition in motion, moving with the story. You've not halted the reader to explain things; you've moved the reader along with the characters and in the process given information,
If the Assembly is a normal part of the world, I'd avoid explaining it. There's plenty of analogues to such a thing in our world, the Congress, etc and the reader will figure in out. If several Assembly members are you can say the "The wizard Podstock addressed the..." and "General Thrimble said..." and that says that warriors and wizard form the council. If the Assembly is secret, then you might want to explain. Someone addressing the group might say, "As we all know our society came together 4000 years ago to address the threat of the Great Night and..." That's something a person might actually say and just gives a hint. However, if the main character is a student then someone can fully explain everything and it's not a dump. Runes: If the MC is new to the runes then they need to be explained. Plenty of people have asked others "Why is cocaine illegal" and a lengthy discussion resulted. Many can't accept something is illegal unless it's fully explained and it's perfectly normal in this situation. If you MC is in a "police" role, then even more so. If your MC is already a Vet, then I think you have to show why the runes are illegal through someone using them, or him recalling cases where they were used.
If it jolts the reader out of the world and makes them think, "this guy is just explaining some idea he had to me!" is pretty much the line. Just having action that leads smoothly into the explanation or even contains it is the most common way. If you have the space, hint for a long time. I wrote the intro to my story with some characters raiding a town - they started apparently moving stealthily, but soon they were just standing there before stealing something when someone wasn't looking at it, and then I reveal how lightly they're moving when one of them jumps from the ground to a roof in one movement, and only after a page of theft do I reveal they're invisible and magically altered in a way that would be spoilerific to just post here, but explains everything. I could have just said, after a few lines at the opening about bad science, "So yeah, we were altered into this crazy thing, and now we're cursed like so," before just having the raid over in a paragraph or two to move onto the important plot thing that rises out of it, but I figured that was grievously unsubtle, and so took the extra time to show them in action so the explanation feels both earned, rather than dumped, and doesn't have to come with a "because we're like this we can do this that and other" since you've already seen them doing it, and therefore... I don't have to mention it. My readers aren't idiots, they'll figure it out because I'm not being so obtuse about what the curse is in the book by far. So yeah, instead of an info dump, one page of action, and then a single line to clear up a couple of things about what they were exactly, and off we go again into the story. Much cleaner.
It all depends on whether you are managing to carry the readers with you and keeping their interest. If you do, they won't see it as infodump. The opening of Steinbeck's East of Eden is masses of information about the Salinas Valley. The opening of Garrison Keilor's Lake Wobegon Days is a mass of information about Lake Wobegon. The former works because it's beautifully written, the latter because it has a dry wit and elements of incongruity that keep the reader engaged. A lot of the Guide stuff in Douglas Adams' Hitchhiker's Guide to the Galaxy is pure information but is hilariously funny. People will only complain about infodumps if they don't like what they're reading. What works for you depends on your writing style, ability and your readers preferences.
If it starts becoming a tangent and looses the reader's interest, I think you've definitely got too much and either need to scale back and try to make it so the information is not as dumpy.
It may help if you weave the information in when it becomes essential or habitual for your viewpoint character to address it. So it's not that you're dumping info on us and pulling us out of the scene, but the information is brought up in the first place because the current scene calls for it.
Info-dumping is bad, and exposition is good. Just like terrorists and freedom fighters. What was so hard about that?
Sounds like you are writing a fantasy, in which case I can highly recommend the book "How to write science fiction and fantasy" by Orson Scott Card. He explains how to handle exposition elegantly within the framework of speculative fiction. To paraphrase what is advised (in case you can't get the book), he advises against 'infodumping' and favours the approach of letting information unfold as the story unfolds. I'm sure you've read lots of fantasy, so you'll know how information is usually conveyed: an unfamiliar term is mentioned, the reader knows it's a new thing, and they wait patiently until the meaning becomes evident. Infodump characters are OK, as long as they're well done and not obvious. There's nothing worse than reading a story knowing that someone is conveniently there to answer all the questions (ala Dan Brown). In short, I'd recommend just get on with the story and don't worry about explaining back story, the right time to drop information will fall into your lap.