If a fighter has a +1 sword that only gives that plus one if he does an exhausting practice routine in the morning, he's liable to ditch the magic sword and just use an old fashioned chunk of steel. Rather than being wore out and need to rest a couple hours before he gets started just in case he needs that plus one, he could just strap on a blade and ride off without having to deal with all the issues. (From Something Agar said)
The Omen Star: In the West, in what appears to be an eccentric orbit, appears the Omen Star. The appearance of the Omen Star in the first house of the sky bodes "great things" for good or ill are about to happen. It is the rest of the stars that determine if it is for good and ill. Thus people are always looking for things to happen during the time of the Omen Star.
If you want to add a "supernatural" touch to your campaign, define the rules of magic and the universe. Make your players comfortable with those rules. Then your new supernatural creatures must then break those rules.
Magic should have side effects, both expected and unexpected - fortuitous and deplorable. Expected side effects add anticipation, while unexpected ones increase the drama of the scene. The result can be comedic or dire, it dpends on which circumstances work best for your game.
Believable magic, like ordinary physicis, operates according to some invariable laws that always result in some kind of cost or "bounce back". The grater the magic, the more it should cost the character physically, emotionally, and spiritually.
"Binding the Life Coil" is an ancient quasi-mystical technique rediscovered to prolong one's life at the expense of one reproductive ability. It is a simple magikal technique that anyone can learn (a skill or feat). The promise of near immortality or a lifespan of a thousand years or more makes everyone want to learn it.
This technique has a price though, the amount of immortality is in direct response to the strength of ones reproductive spirit. Those that have never breed will live longer than those that have. The use of the technique makes conception difficult, if not impossible. So you trade the future of your society for the chance for you to see much of that future.
Also called "pale-yellow witch" by alchemists, this mineral is known to possess a peculiar attribute. When found, a Yupiorite will appear the palest yellow. Rather than crystalline in structure, Yupiorite occurs in weird, smooth, ovaline shapes, as if already carved by skilled hands to serve as ring or necklace ornaments. Yupiorite somehow detects and reacts to mood. When the wearer of the gem is content, calm, and happy, the stone will remain the palest yellow. As the person gets more excited, angry, or otherwise stimulated, the mineral will darken progressively to a dark corn-yellow in color. Why the gem reacts this way to sentient mood swings, is still debated by gemologists and alchemists alike.
It is said that the Elven Halls of Vala-Aluduwy are resplendent with wall-sized mirrors of pure Yupiorite, showing plainly and ironically, the emotions of everyone present, despite the Elven love of restraint and stoicism.
"Cave-grass" or "cave-pine" is a deep forest green in color, rare and often mistaken for other minerals, though otherwise mundane. Crystals form into tiny, ultra-thin, needle-like clusters by the hundreds of thousands, creating vast dark green bursts and structures, resembling evergreen conifers, if viewed by any sort of light. Despite its ephemeral shape, Aragdulose is only second to a diamond in hardness.
Dwarves are said to keep these mineral "trees" in their homes, putting them up during festive family holidays, leaving presents beneath them, for kin to open.