Why DnD for a modern horror-ish game?
I want weird dangerous stuff to be 'scary' because it's weird or dangerous. I don't want to to be scary because your Hype Meter ticked up. I want a dude to be scary because you saw him take 3 pistol shots to his t-shirt covered chest and a little grease came out of the wounds and he seems fine.
|open source image from wikimedia commons, photomosh'd by me|
Why 0e DnD?
It's really cool. 0e is not a complete system unto itself. People make hacks of it. It doesn't proscribe how to run a game or whether your PC can be 'trained in forest navigation.'
What else tho
I kind of want to eschew hp progression, or at least the idea that you go from level 1 to level 9 and suddenly no one with a knife is a threat.
I love system/setting things like Troika, and there are some cool modern urban fantasy-ish hacks, but I don't really want the PCs to start out as supernatural weirdos. If you have a half-vampire as a PC then half-vampires aren't scary or different or horrors. If you get bit and fail a save and turn into one during play, that's fine.
I've categorized these games by big obvious things in their dice-rolling mechanics because I care deeply about things that actually don't matter.
d20 roll high or die
Luke's rules. These are good, really close to 0e but clearly their own thing, but largely compatible with things like hit dice, saving throws, to-hit, armor class. No classes, magic is _dangerous_. Only 3 stats: str, dex, con. 3 saves: warding, dodge, physique. Some progression but can just do it via 'heroic boasting' in another post of Luke's. The closest to normal-ass 0e DnD on the list so far.
Dungeon Gig. 1 stat which is your HP, also is what you add to a d20 roll when your background or skills apply. Also the damage you deal and inventory slots. Starts between 1 and 6. HD compatible, map to 1 thru 10. Open license. LATAM creator. Solo rules, plans for expansions. Learning a spell decreases your stat by 1 permanently, have to spend health temporarily to cast. Roll d20 only, roll high.
(Un)Level. 3d6 in order stats, no indication what they're for, you get saving throws, you are level 3 forever, you get 3dx HP + the length of one of the words you used to describe your class/background. This is very cool in its brevity. Things aren't dictated or even hinted at. I'd steal a lot of stuff from Delving Deeper and Liminal Horror and run this like a stolen car.
DURF. 3 stats (Str, Dex, Willpower) 1-3 at start, HD compatible, no HP, you roll HD with every wound and if you don't roll over your current number of wounds with any hit dice, you die. Hit dice are all 1d6. So a neat way to let HD grow without PCs becoming a giant mass of MEAT POINTS. Casting spells causes 'Stress' which takes up inventory slots. Can also take stress to take advantage on a roll.
Delving Deeper. It's a 0e retroclone. I'll at least use it for reference. It's got the 0e monster manual and all the ship-combat rules you'll ever need.
Sometimes over sometimes under
Bastards. Roll-d20-under-stats, 3 stats (str, dex, wisdom). Luck is a stat, roll d20 under, reduce luck by 1, restored in the mornings. Use as a Save. Roll under but above opponent's HD if, say, trying to sneak past the Lich or cast a spell on it. Gain 1d6 hp every other level. Enemies get a to-hit roll in a fight (roll under 10+HD), a nice change from some other roll-under-stat systems. The stuff with opponents HD and the sort of roll-above-and-below is brilliant and understated. It makes it harder to sneak up on a lich than a goblin because, you know, fuckin liches suck.
A Dragon Game. Roll d20 under-but-as-close-as-possible-to-stat, HD compatible, fighting is _super_ deadly. Learning magic degrades your stats or HP. There are some enemy hd/HP adjustments to make because the d20 roll is also the damage roll, if your attack hits. Players roll only, attack and defense separately. Perhaps closest to a straight-up horror game. Progression is milestone-ish, and you either increase HP by 1d6 or try to increase a stat, which has a 5% of gaining HP. Open license. Getting attacked is hella lethal, perhaps the lethalist. Has a cool supplement to make dying instantly less common but your character gets eroded away by violence.
17th Century Minimalist. Roll under, no real magic for the starting PCs. HP is hard limited, as is non-magical damage. Classes would probably need some reworking to fit in ze modern era.
Chainmail just used d6s right?
Murdersoup Tales of High Adventure. 2d6 game, not HD compatible but has ideas for HP for normal folks (1d6), adventurers (2d6) and monsters (go wild). Damage follows a similar trend. HP growth through hitting 0 HP and not dying. Cool stats in Murdersoup Heavy Metal Adventures - basically the Apocalypse World ones, you roll to see which one you're best at. Some cool ideas, generally roll and try to beat a 7 to 9+, ToHA has very minimal addition rules for rolls (+1 to ranged attacks for good dex, that sort of thing).
0E in space is Traveller, Traveller is 0E DnD I DON"T MAKE THE SCIENCE RULES
Advanced Fighting Fantasy Was 0E for the UK
Was Warhammer 0e? (YES)
Sledgehammer. d100 based, wounds and corruption, not 0e-compatible or trying to be, but has a very cool Warhammer 0,000 vibe. 4 stats: fight, speed, fellowship, toughness. Stats are low, only players roll, failing a to-hit roll means the monster hits. Not HD compatible, monsters have two stats (damage and health). MA Guax is making a modern hack (Freaks on a Leash) and put out some stuff on his twitter about a deprecated/lost modern hack (Slickhammer) which both ROCK. Open license. I feel like the limited number of stats gets this away from 'roll under Int/Wis/Cha/Str/Dex/Con' like I see with some things, and you get some neat room for rulings that way.