Magic Metals and Stuff

You know what's a cool fantasy trope that everyone likes? Magic metals. Made-up metals. Those things. It's true. Tolkien gave us Mithril and it was cool and people kept it going. There's Vibranium. They make a big deal out of it in those Marvel movies. Game of Thrones has Valyrian Steel, and every time it comes up the dialogue always sounds really forced and fake. Like they're trying really hard to make it a cool thing but it will never be as effortlessly cool as adamantium. But whatever, it's cool. Meteorite swords are also really cool. They give you just a taste of sci-fi but they aren't out of place in a medieval setting.

But like D&D just has +1 magic weapons most of the time. Sure, the DM can hand out a silver sword or something. But just a general +X to attacks and damage and being vaguely "magical" (to overcome resistances/immunities) is what players hunt for. Not that there isn't a strong history of lore behind that. Gygax had some very weird ideas about +X swords*. But I kind of like the flavor behind the magic metals and how specific they can each be.

Anyway this is a perfect trope to emphasize in a system like Knave because it's an RPG all about equipment. Thus, magic relating to equipment and its special properties has a much greater impact in this ruleset. It's good tying together of themes and mechanics. So here are the metals in my Knave game and what each of them does and stuff. Borrow/steal/be inspired by or whatever else.

Materials that some monsters are weak to

1. Silver (looks like: silver): good against fiends and vampires and werewolves and other hell things without souls
2. Cold Iron (looks like: low-quality, brittle iron): good against the Fair Folk
3. Stygium (looks like: bright red metal): good against celestials and blessed mortals
4. Starmetal (looks like: metal with crystalline patterns): good against aberrations and things from outer space/other dimensions

Materials with special properties

1. Mithril (looks like: silver but slightly blueish and really shiny): very light. Always takes up one less slot than normal. Therefore, the smallest mithril armor would be 1 slot and have a defense of 13 (equivalent to brigandine). A mithril helmet and shield can both occupy one slot but they still are treated as separate items. Apply the same logic to weapons.
2. Adamantium (looks like: black metal): incredibly hard. Either add 3 to the quality of the base item or just give it an infinite quality rating. In 5E D&D they also have adamantium always critical against objects and structures, which I like.
3. Orichalcum (looks like: rose gold): magic resistant. Whenever you have something orichalcum taking up an item slot, you always have advantage on spell saves.
4. Cinnabryl (looks like: red, but kind of a brick red. Basically just cinnabar): purifies. Whenever you wake up and have something cinnabryl taking up an item slot, any ongoing poison or disease effects in your body will be removed. Cinnabryl also gives immunity to mutations.
5. Morgul (looks like: brittle iron with dark wisps emanating): Bestows a curse that undead-ifies targets. Only really used for weapons. Constitution save (DC 15) when hit to not take 1d8 poison damage. Repeat the save once every day. If you make it three times, you're clean. If you take 15+ cumulative poison damage, congrats. You're a spooky boi now. A wraith/ghost thingy would be traditional but I like ghouls/wights, and it can be made a lot more Dark Souls-like that way. ALSO it always has a quality of 1, maximum.
6. Damascene (looks like: metal with wavy patterns): really sharp. Also really only used for weapons. Extends critical hit range by +2.

-Dwiz

*See Dragon magazine, issue no. 8, article entitled, "Planes: The Concepts of Spatial, Temporal and Physical Relationships in D&D" by Gary Gygax.