This is a perpetual topic for writers. There are a surprising number of discussions on different topics relating to these.
First of all, is it a point or a mark?
Both, I guess. I don’t know which is preferred.
Next, can you use more than one in a row, such as in the title of this blog?
“Never use multiple exclamation points in a professional setting!!! Again, this is fine to use in informal and personal context, however most professionals agree that there should be ONE end punctuation mark to each sentence. Professionally, it doesn't reinforce the exclamation, it just breaks grammatical rules.”
(Strange boldings there, if you ask me.)
(Really, though, this whole article is good if you want to delve.)
(The article below says that if you’re going to use more than one, use three, never two.)
(I wonder how many parentheses in a row are too many.)
When should you use them and not use them in fiction writing?
Not for emphasis, hilarity, or excitement.
Use the writing to give emphasis and excitement. And using them to be funny is like laughing at your own joke. Or so this site says:
It also says you should use them for:
Raised voices, to make fun of characters, and in writing for children.
Okay, raised voices, I’ll go along with that.
The expanded explanation on the second one is to make sure the reader knows that what you wrote isn’t serious. I’m not sure how this is different than laughing at your own joke, but whatev!
And for children? You know, it’s hard to get them to use those inside voices. Maybe that should be rethought.
Here’s what Elmore Leonard famously said:
“Keep your exclamation points under control. You are allowed no more than two or three per 100,000 words of prose."
photo from morguefile.com