What makes Arthurian fantasy its own genre, different from more traditional D&D-ish medieval fantasy? What are some Arthurian-style plots?

[Reynard]

I don't think that you are giving Pendragon enough credit. It does its homework. The game leans heavily into the source material. It discusses the different versions of the tale, modern and medieval. However, it acknowledges that Malory's Le Morte d'Arthur is the primary inspiration for Pendragon, and the game book littered with quotes from Le Morte d'Arthur as examples to illustrate the inspiration for the mechanics. So hardly just Excalibur the RPG or T.H. White's Once and Future King.

That's fair. I have only played the game a half dozen times in 40 years of gaming. Every time has been pretty banal with mundane knightly concerns overshadowing any (usually fae) magical elements. Every time by different GMs, mind, so that's why I came away with that assessment. I have never owned it or read it.

 

[pemerton]

For me, the biggest difference between Arthurian-esque fantasy and more conventional D&D-esque fantasy is that the latter tends to be cynical, whereas the former is providential. Even when things don't happen for any particular reason, the way they unfold reveals something about who the protagonists are, what their destiny is, etc.

 

[JConstantine]

I was all ready to waffle on about Arthuriana only to see that between @aramis erak, @Tonguez and @Benjamin Olson, what I was going to say has already been said.

I suppose there's a few things I can add to tie it into the OP.

I realize that my lack of knowledge of the genre isn't helpful.

The Knights of the Round, combined with Charlemagne's Paladins are a core inspiration for D&D's Paladin, just without the divine magic. I want to highlight this:

Knights and Heroes in Arthurian Fantasy are called to quest in order to test their ideals and prove their worthiness and honour. In such quest no encounter is random, they are all “fateful encounters” designed to highlight the heroes true nature.

So whatever quest you'd want the most lawful and goodly Lawful Good Paladin to undertake, mixed with elements that are explicitly designed to tempt them to fall, is likely appropriately Arthurian. The difference is that failing to uphold one's virtues doesn't lead to dark magic powers, but rather contribute to societal collapse.

@aramis erak is correct in that the Matter of Britain doesn't present much in the way of horror per se, however, I think it can be done by tying it into the notions of chivalry. That is, as long as characters are maintaining virtuous behaviour, the horror elements are kept at bay, and engaging in unchivalrous acts allows malign influence to spread - essentially, the horror should be occurring to the characters because of their own self-indulgent actions. Since you'd be using Daggerheart, I'd probably want to tie this to the Hope and Fear mechanic in some way, but the way they're generated by dice rolls is rather at odds with the determinism of character behaviour. Maybe generating additional Hope for chivalrous deeds and additional Fear for unchivalrous ones?

 

[JConstantine]

Yeah, I don't want to have to buy an entire game just to get a few tips on what adventures are like. Thanks, though.

The author of Romance of the Perilous Land has some supplemental material on their itch.io, including a couple free adventures you might be able to repurpose.

If you have time, you could watch episodes of Prince Valiant (YouTube playlist) for inspiration.

 

[Distracted DM]

The author of Romance of the Perilous Land has some supplemental material on their itch.io, including a couple free adventures you might be able to repurpose.

If you have time, you could watch episodes of Prince Valiant (YouTube playlist) for inspiration.

I did not know that there was a Prince Valiant show, I only picked up the collected comics a few years ago.

 

[Tonguez]

Since you'd be using Daggerheart, I'd probably want to tie this to the Hope and Fear mechanic in some way, but the way they're generated by dice rolls is rather at odds with the determinism of character behaviour. Maybe generating additional Hope for chivalrous deeds and additional Fear for unchivalrous ones?

I'm not an expert on Daggerheart rules but maybe have each character start play with 2 Virtues which the player gets to invoke for bonus hope eg Courage - Hope: Roll a bonus hope die when standing against overwhelming odds.
But: Take stress when your recklessness results in others getting hurt.

Stress makes for a good temptation/corruption tracker too

"You fail to show Mercy and your Honour falls - mark Stress"

NB: just outright rename Stress to Honour and use it as such
(so you use honour for abilities and lose it when using spells)

 

[JConstantine]

The best movies for reference: Excalibur, First Knight, Tristan & Isolde (acting's so so, but the visuals are very period). Disney's Sword and the Stone is decent if more fantasy. The Name of the Rose is excellent, if not properly Arthurian, just like T&I.

I'd add the 1998 miniseries Merlin, starring Sam Neill. It takes some liberties, like adding Queen Mab as sister of the Lady of the Lake and antagonist, but Miranda Richardson's portrayal of Mab along with Martin Short's Frik are a great portrayal of malevolent fey.

Arthurian Games: Everyone's already mentioned Pendragon. it's got a great timeline to steal.
Scott Malthouse's Romance of the Perilous Land has a similar, but earlier set, timeline, and a ruleset that looks hybrid of Dragon Warriors and D20.
I, Mordred. Hard to find, but an excellent adaptation of Arthuran to D20; add Noble Knights and Noble Steeds, and you get a decent Arthurian D20 (D&D 3.x) experience.
Chivalry and Sorcery, Wilf Blackhaus. (several publishers). It's grounded in arthurian, but is more properly medieval.

To expand this, there's also:
Keltia from 7th Circle, using the same 2d10 system as Yggdrasil and Qin: The Warring States
Mythic Britain for RuneQuest/Mythras
And the upcoming The Winter King - a post-Arthur uchronia of sorts where Mordred is king. Free quickstart.

Mallory, Sir Thomas, Le Morte d'Artur - get it in a translated edition for easier reading.

Alternatively, there is the Arthur Dies at the End series of books, a sardonic retelling and critique of Mallory's work, because as seminal as Le Morte d'Arthur may be, by the Grail is it dry.

 

[DrunkonDuty]

I'm fond of the older, more fantastical aspects from Celtic myths. In those Arthur's knights are always travelling back and forth to Faerie and dealing with strange beings. I think it's a trope that would mesh well with the Mists of Ravenloft, with Ravenloft obivously being Faerie. Playing up the cold, uncaring Otherworldliness of the Fae should give more than enough scope for horror too.

But I'll echo what others have said and say it's important to play up the fateful aspects of the adventures. Everything is testing the knights. Again, sounds like something that works well with existing Ravenloft canon/adventures.

 

[Edgar Ironpelt]

You might not want to use the system, but I'll suggest GURPS: Camelot, even if you just want background material, including notes on three different variants of "Arthurian fantasy." SJG still sells it as a PDF: GURPS Camelot

 

[JConstantine]

-Villains are "Black Knights". The majority of human antagonists are evil knights, and the central antagonist is basically always an evil knight (lords are themselves knights). After all, defeating some mere bandit isn't very heroic, our protagonists need ostensibly equally matched opponents. Who's kidnapping those damsels? Black knights of course. Where is the treasure that needs to be recovered? A castle full of black knights. Often their evil has no stated purpose.

While "Black Knights" are often the villains - or villeins - it should be noted that antagonists in Arthurian Legend aren't always such obvious enemies. The Lady of the Lake exploits Merlin's love/lust for her to have him teach her all he knows, then uses magic to capture and either kill him or put him to sleep. Elaine of Corbenic uses magic and deceit to "seduce" Lancelot (leading to the birth of Galahad). Actually, just a whole lot of magical seduction leading "virtuous" men astray.

-Hidden Indenties. Protagonists, and people they meet, are often unwilling to divulge their name and identity until some key moment. Often this is so that they can prove their worth for acts of prowess before being lauded for their illustrious name, but it's also a whole trope beyond that.

To expand a little, the hidden identity tends to lead to some sort of problem, particularly as it's often done with less than chivalrous intent - either false modesty, or an attempt to deceive. The consequences can be as drastic as a knight killing their father/brother/son/friend whose identity was unknown, or as ironic as swearing an oath to protect an enemy (tying back in to that weird oath trope)