Enchanted Item: Cat's Ring

Picture of the ring from the game.

Introduction

So, starting simply on a list of items, I begin with the Cat's Ring from Demon's Souls. This is probably as straightforward as straightforward gets when it comes to converting an idea from a video game into GURPS mechanics. Let's take a look at the flavor text of the ring to understand its intent:

A simple ring engraved with the seal of a cat.
It decreases damage when falling from high places.
However, if you fall from too high a perch, you will die in the usual way.

That seems straightforward enough, and it is almost a 1:1 correspondence with the advantage from GURPS, "Catfall"

Catfall [Physical] [Exotic] 10 points

You subtract five yards from a fall automatically (treat this as an automatic Acrobatics success – don’t check again for it). In addition, a successful DX roll halves damage from any fall. To enjoy these benefits, your limbs must be unbound and your body free to twist as you fall.

Calculation

So, besides being slightly more flavorful and setting specific, to me, this sounds like a good match. So what I'm now going to do is pull up the Sorcery Book which tells us how to make a magical piece of equipment. Sorcery specifically depends on powers that are fueled by FP, but we are not going to worry about that, because we want to mimic that the utility of the rings as they work in Demon's Souls. Additionally, it is traditional to associate a Magical modifier with an enchantment. This modifier is worth -10%, and for all intents and purposes what it means is that if we are faced with a situation where we are deprived of mana, the enchantment will simply stop working. That is, if you are in a place devoid of magic, this ring does not give you Catfall.
The 10% discount means that Catfall is now worth 9 points. We further know this enchantment is going into a ring. A ring has certain advantages and disadvantages associated with it that sum up to a discount of 35% as detailed by Page 28 in the Sorcery manual, or a multiplier of .65. .65*9 = 5.85. This number is our "Enchantment Points" or EP and describes how hard it is to create this item among other things. We want to round this number to an even 6.
I am going to assume for the purpose of this calculation we are technology level 3, a particularly good match for Demon's Souls. Technology Level 3 (or TL3) represents middle age technology. Knights, castles, cathedrals, monarchies, the like. If we take a look at Page 30, we can find a list correlating the cost of raw materials required to EP level, 6 for TL3 requires $50 worth of raw material. That part isn't so bad, but look at Page 33. We haven't accounted for the cost of creating a magical ring. Each EP in TL3 is worth about $320. What this basically means is that the labor to actually enchant the ring costs $1,920. The total cost of the ring adds up to $1,970!
Note that I say cost. This is how much money is needed to create the item. The section explains that a merchant that sells magical artifacts actually hopes to make money. So that means they need to sell the ring for a little more. The book suggests potentially doubling the price.
So in the end, a magical ring that bestows the Catfall advantage on a user costs $3,940 at retail!
Additionally, there is the 6 EP still. As a suggestion to GMs, this 6 EP represents a balancing mechanic. If players can acquire many exotic, point heavy advantages easily, it might throw off game balance. One of the recommended solutions in the book is to require players to pay EP character points (or EP/2 character points) for Signature Gear if the GM wishes. This is solely a GM's discretion, and in something like some Dungeon Fantasy games, it might not be necessary at all, but it is an option in the GM's toolbox if balance is a concern.

Conclusion

This was a very easy example of how to fairly price a magical artifact in GURPS. All that was required in order to do this is the Basic Set - Characters volume, and the Thaumatology - Sorcery supplement. More complicated examples might also benefit from the GURPS Powers volume, but this was EZ PZ. Bottom Line: In a medieval sword and sorcery type world, a ring that lets you jump safely from high places probably has a fair asking price of around $4,000.