Are there any well-known novels that originally started as a roleplaying campaign?

You sure you don't have that backwards?

Yes, I am sure I don't have that backwards. The first Expanse book was a slog and I couldn't even finish it. I burned through the tv show in 2 days, it was that good.

Record of Lodoss War is not well known in America, but is it's own little franchise in Japan.

Started as a replay of a D&D campaign printed in a computer magazine. It became a novel series, and then produced various anime, manga, and video games.

I don't think we got the novel, but we got one of the OVAs and a Dremcast game at least.

Amos is best husbando I love the actor's portrayal

The expanse

The Lord of the Rings was originally a Dungeons and Dragons campaign that Tolkien ran, hence the presence of D&D aces like dwarves, elves, orcs, and halflings.

True story!

He's such a fanatically-loyal psychopath, it's great.

I haven't confirmed it, but I am almost positive that 'chronicles of the black company' was a game first, it reads like a campaign that the players wouldn't let the game stop playing. Also many solutions to problems are totally in line with 'stupid pc ideas' threads.
Malayan books as mentioned before, were pulled from gurps campaigns.

Not a Novel but sure as hell has enough text to fill one:

Pathologic was originally based off a PnP campaign. All the player characters were PCs plus 2 others who became major NPCs in the game.

Feist's Midkemia books/pc games started off as a pnp game.

Not a novel and not confirmed but im certain that Guardians of the galaxy was based on some kind of RPG game some dudes had.

kek fuckin 10/10

Not a novel but the Overlord anime/manga/long-novel are based on a guys D&D group.

It's a pretty decent setting all in all, I've stolen many bits of it to use in my own.

It may-- and this is just me thinking out loud-- but it may have been inspired by the Guardians of the Galaxy comics that existed well before the movie.

Forgotten realms

E.Y.E Divine Cybermancy arguably counts.

Valdemar is from the 80s, birth right is 90s, are you aging in reverse or some other time travelling shenanigans?

Record of Lodoss War. Literally someone's homebrew D&D campaign.

Slayers. Literally a transcript of someone's homebrew D&D campaign, complete with outtakes.

Fate/Stay Night. It was originally a modified version of AD&D that Nasu et al played.

Shit, you're right. First mention of The Iron Throne in Valdemar series (either Winds of Fury or Storm Warning, I can't remember which) predates Birthright by 1-2 years.
However, Game Of Thrones was published in 1996, so my point there still stands.
Pretty sure Valdemar was an AD&D game though, where everybody important got to roll on the psionics tables.

Mein Kampf

Wasn't the Bible based on a free form RPG?

No, it was Bible Black that was based off of free form.

Amos isnt a psychopath, he's just traumatized from his childhood and probably autistic.

He can still tell right from wrong, it's just not the right and wrong that mainstream society deems acceptable.

The Rift War series is based off of a tabletop game.

It'a an easy mistake to make.

...I have additional questions.

>Fate/Stay night.
>Modified version of AD&D.
It is not that I find F/SN based off an TTRPG campaign hard to believe, but AD&D... it simply ain't right.