You might get away with slow and dry speech if you're writing a general fic. For crack, that is a big NO-NO.

If nothing else, keep these in mind:

Voice.

If your exposition puts people to sleep, you might as well be writing nonfiction.

No, seriously.

This should really be a big point whenever you're writing any kind of fiction, but crack really can't do without it. It livens up anything you write and keeps your reader interested even if what you're saying isn't all that interesting.

For instance:

"The dungeons are 12.45 miles northwest from the castle."

That is something you might see as an answer on a physics test.

So try:

"Now, it was rather unusual, but the castle dungeons were located a few miles away from the actual castle. Yes, it’s unconventional, but it’s more convenient for the author of this story if it’s that way. So, it was kind of tough to communicate with the dungeon-master, Donghae, but the king and queen didn’t really care because it wasn’t them doing the work anyway."

In the second example, the author is actually engaging with their reader. It's longer and less simple, but it's considerably less dry.

Confidence.

It’ll make people think you’re actually funny!

(for example, if you think I'm funny in my writing, that means it's working)

If you don't even think you're funny, there's no way your reader will. That also brings me to another, very important point:

Whatever you do, DON’T EXPLAIN YOUR HUMOR!

We all know how having to explain a joke after you made it will just kill it:

"Why did the chicken cross the road?" "I dunno, why?" "Because it was running away from Onew! OMG GET IT, GET IT???!!! BECAUSE ONEW LOVES CHICKEN A LOT AND WILL NEVER LEAVE IT ALONE! AHH OTP <3"

Trust in the intelligence of your reader. If you have to explain yourself, it’s either a lousy joke, or you should explain it in the footnotes. (Footnotes should be used mostly for vague allusions. Don’t use too many of them and DON’T EXPLAIN THINGS IN PARENTHESES! More on parentheses later.)

So, subtlety is key. Don’t be blatant, because that ruins the illusion that you're confident in things your saying.