Friend is running his "Quest for the Grail" homebrewed PnP game.
Inspired by our playthrough of Dark Souls, it's a mashup of that and the movie Excalibur (1981.) You all play knights of King Arthur's roundtable, set off the quest to find the Holy Grail. You aren't the first to do so, and you likely won't be the last.
Character generation largely is done with a deck of Tarot cards, and they flavor many GM decisions when he chooses to go the deck for randomness. Your Major Arcana determines your base character traits like "Strength", which is your health, starting "Skill" points and some core character abilities like double damage or power mimicry or endless supplies or whatever. The minor arcana further adds some skill points and makes you a specialist badass in some knightly trait.
Skills are interesting in that they are all knightly skills, so riding, hunting, sword play, courage, etc....then there are knightly virtues like chastity or patience or temperance, which can come into their own related tests when called upon. Then you have 4 stats for the 4 elements, and 4 stats for 'humors' like blood, bile, phlegm. They're all "skills" in the sense they can be called upon, tested or used as a basis for bonuses to actions or to determine who has the advantage in contested actions like combat. So you might get a bonus to doing a blood ritual (heaven forfend) if your Blood stat is high....but it also might give you a penalty if you, say, cut yourself on a devil plant.
Lastly you have DOOM. Doom is a catch all penalty for the whole game. Everything ultimately leads to your doom. You acquire doom points as you play and make roleplaying choices and the quest progresses, and test against it constantly to see what happens. Generally Doom is just that, you're dead or out of game one way or another if you blow the roll. It's unclear if it can just penalize you. But if you're in combat and you exhaust all your strength, you'd be called on to make a doom roll. Fail it and the enemy probably runs you through, beheads you or whatever. Succeed at your doom roll and you're just knocked down. You gain some doom, and get up again with a little strength restored to try to fight another round.
The final kicker to the rules system is you can convert your all stats (except doom) into experience. However if you spend 'Humors', you gain Doom. Acquire enough experience, you gain a level. Level is effectively a straight bonus to all rolls. Initially it's a smaller portion of your combined chance to succeed because you start at Level 1. But for example I drew the Judgment card for my arcana...which gave me 0s in all skills but started me at Level 7. So while most players were rolling with a +3 or +4 to their die rolls at best counting all circumstances, I was rolling with a +10 even though I effectively had "skill" in nothing.
It's a pretty enchanting little system with a nice closed loop of advancement, where he hands out micro rewards during gameplay unlike pretty much every RPG I've ever played. Woo a wench? Your choice of 1 point in x, y or z skills. Show faith and devotion to god? Get a point of Faith. Do your duty with honor? Get a point of diligence. Generally if you act in unknightly ways (he had every character sign their name to a sheet of knightly oaths he sourced from somewhere on the internet) you get Doom. Since skills function as both skills and experience, you have to weigh the advantage of being stronger at one individual test by letting your stats grow, or becoming more effective at all tests by turning them into XP, and eventually levels. When you fail tests, you generally earn XP. When you succeed, you earn skill points. The system is a little floaty and generic as is his way with most games he designs, characters are very fluid in their stats and makeup, but it's got a nice little reward mechanic which rewards roleplaying and straight combat/adventurey type stuff equally for doing the things the player wants to achieve, be that sleeping with maidens, training, praying and devoting themselves to God, acting with honor or with a level head. And even if the thing you're doing never gets called on very often (let's say charity or chastity) you can still turn those skills into better overall effectiveness, so you don't get left behind by people that just want to hit stuff real good. It nicely side steps the "I play a bard in a party full of kill bots and I'm totally outclassed because I'm playing an actual character" problem so many games run into.
It might create a sort of neediness on the player's part to get rewarded for literally praising God all the time, and require some thought on his part to reward people that don't participate as much or as vigorously. But because he's essentially broken experience gain into morsels that also provide short-term advantages as well, it's something he can control the flow of while also not stiffing his players on any kind of meaningful advancement. There is no level cap, so in theory the system is infinitely extensible.
Doom is also a nice mechanic because, not only is it totally thematic to the endless suffering and eventual death of the Grail Quest, it's a weight against doing risky things. A player stole magic items from Merlin tonight and with some amazing die rolls, got a magic item right at the start of the game. But it earned him (comparatively) a lot of doom. He went on to utilize this item in a fight and it eventually got him killed.....by just the amount of doom he earned stealing the item in the first place. So with all this kind of freedom to get better is the weight of guaranteed death hanging over you, so it becomes a race to see who can live the longest and get the strongest and be the most legendary knight of the party that everyone remembers.
The setting is cool too. It combines the sort of dreamlike setting of Dark Souls with the allegorical, fantastical and mystical trials of the Grail Knights. (He really, really drank deep of the Dark Souls koolaid.) He's completely dialed in to the vision of endless hordes of Grail Knights throwing themselves at the impossible task of finding the Grail, leaving a trail of armored corpses across the land. In the first session one player managed to "die", and rolled up a second character immediately, who was literally a knight we pulled off an impaling spike that was still alive. So fuckin' metal.
So yeah, between his rather clever and eminently flavorful system he's cooked up specifically for the game and the setting, which oozes with mysticism and gives you that quest of torment Dark Souls vibe, I'm more excited for the rest of this campaign than many I've played in a long time.