User blog comment:TheNewProtagonist/Dust is actually kinda dumb./@comment-9090085-20130814014527

Just because you haven't been told the rules, doesn't mean they're not there: we don't know what happens when someone blends dust because it hasn't come up in the series yet. What were you expecting, a 10-20 minute explanation of all uses, functions, and limits of Dust? If they did a huge info-dump like that, especially this early, people would get bored and not watch the show. Never mind that info-dumps tend to bury the important information you need to know beneath the huge number of facts, that while interesting, are not necessary to enjoy the show. It's much better to tell us what happens when you combine Dust types when someone tries or considers trying, not in the middle of nowhere and buried by a bunch of other facts which were more important to know when you were being told.

Let's be serious now, do you really need every single detail how something works to accept it? Do you know the exact mixture of chemicals used in gunpowder? Do you know every single component in a jet airplane? Do you know the particles used in a phaser? Do you know the physics behind the warp drive? I will assume "no". And does that render the series unwatchable? Of course not; that you know the what they do (kill; fly; kill or stun; travel really fast), and that what they can or cannot do is not contradicted later in the series, is enough for you to accept it without needing a 500 page textbook.

And, as many people have said, just saying "a wizard did it!" is a huge narrative cop-out; when the wizard can just wave has hands to make things happen, without limits or rules, what's to stop him from solving every problem that way? Nothing. Just create a new "spell" from scratch to solve your current problem right that instant. By having rules, you can insure that the audience can be involved in the series, working out what happens and how to solve problems alongside your characters.

A good example of "magic" with rules, IMO, is the Mistborn Trilogy by Brandon Sanderson. In it, there are "Allomancers" who burn(consume) metals in their bodies to produce specific effects: burning iron lets you pull metal towards you; Tin enhances your senses, etc. and we know what happens when you incorrectly mix metals to create, say, steel is: you just get sick when you burn it and has no other effect. Of course, we only know what our characters know: we don't find out about Feruchemy(a "magic" system that stores attributes for later use)  until a Feruchemist appears and explains it, and only in the third book is Hemalurgy explained, but both appeared long before they were explained, and those explanations fit with what we saw them doing before they were explained. And of course, these were explained when it was important you you to know, not dumped in a huge block at the start (like the mixing metals is brought up when a character looking for a mixture he doesn't know and is carefully researching).

Of course, if you still want a cop-out/simple explanation for how Dust works, think of it as a crystal/powder imbued with magical energy, and most people use Dust to power technology until the energy runs out.