Actually, scratch that. It is good for the players to know that they're in a world in which there is something going on beyond them. Even if they don't understand the economics, how much more interesting is it to hear that the orc was carrying "silver coins which seem to have been minted by King Ulmer of Ulmerland, judging by the inscription - I wonder how it got hold of those, not being from those parts?" than "five silver pieces"? I remember a beautiful essay in the 2nd edition AD&D DM's handbook which said pretty much the same thing, describing the treasure chest of a minor nobleman in medieval Europe, and how it might consist of everything from old Roman Sestertii to Byzantine Solidii to Scandinavian hack silver. Treasure is a part of the game generally taken for granted by DMs and players (except when it comes to magical items) but to do so is to miss out on a big piece of the verisimilitude puzzle.
I was just idly clicking wikipedia links earlier today (is there a verb for this? wikisurfing? wikitimewasting?) when I came across the entry for Lapis Lazuli, the famous semi-precious stone. I hadn't known much about it before, but thanks to the wikipedia entry I know have a wafer-thin sheet of superficial expertise in the area (I'm a wikiexpert?) that I thought I might put to good use on another - probably final - goblin entry.
In our world, Lapis Lazuli has been mined since pre-history in the province of Badakhshan, in Afghanistan, where it is still found today in quantity and quality unrivaled. It was possibly the ancient world's most popular gemstone (although it is actually a rock), because not only is it beautiful and easy to work, it also had a lot of important applications - everything from royal seals to aphrodisiacs to blue paint (for a long time it was one of the only sources of blue paint available to artists). Due to the desire for the stone, Badakhshan became the centre of a web of Lapis Lazuli trade which stretched all the way from Western Africa to the borders of China. The Silk Road ran through its high mountain passes, spreading the prestige of the Tajik miners living there.
Nowadays, of course, Lapis Lazuli isn't as important as it once was and Badakhshan is a small backwater province in one of the poorest countries in the world. (Although apparently even during the Soviet era, Tajik Mujahideen were selling the rock to fund their insurrection.) But not in my fantasy world!
The Goblins of Nurkalah
For millennia a race of goblins has been mining the mountains of Nurkalah for Lapis Lazuli. The rocks they produce are unparalleled in quality, and can be found as far East as the dwarven Shogunate of Hiraizumi and as far West as the halls of the Fir Bolg king. The lapis passes through many hands, and over great distances, to get to its final destination - on the backs of camels, mules, yaks and griffins, across mountains and deserts and forests and rivers - and many of its users know nothing of its origins. The young wife of the Count of Ross would be shocked to discover that the beautiful, vibrant green brooch she wears to pin her shawl found its birth under the pick of a small, fiery-eyed goblin five thousand miles away.
The goblins of Nurkalah have been mining Lapis Lazuli so long that their behaviour and physique have adapted to the work. Smaller even than normal goblins, they are so used to hunching over in narrow tunnels and scrabbling around in piles of rubble that they have developed an almost simian appearance, equally at home on all fours as on two feet. Their lungs are perfectly suited to the high altitudes in which they have to perform their back-breaking work. And their strength and endurance are vastly greater than that of ordinary goblins.
Lapis Lazuli, as all know, is an aphrodisiac, and the goblins of Nurkalah are not immune to its effects. And as they breathe in its dust constantly, they exist in a permanent state of heat. They breed explosively, so much so that their numbers are constantly threatening to overwhelm their geographical resources. The creatures solve this problem as only goblins know how - mass suicide. When their population is too great to be sustainable, vast numbers of the goblins mass together on high cliff tops and together hurl themselves, lemming-like, to their doom. The days and weeks before such events are wild affairs in Nurkulah, as the goblins rush about trying to fulfill every last urge - to breed, eat, drink, kill - before their life is over.
A Nurkulah Goblin is similar to an ordinary goblin, but gains a +1 bonus to damage rolls due to its great strength. It has an effective dexterity of 18, and can climb rock faces almost as quickly as it can walk.
If a tribe of Nurkulah Goblins is encountered, there is a 5% chance that it is preparing for a mass suicide event. During this period the goblins will be utterly disregarding of their own safety, which means that in a battle their morale moves up to 20 and they gain a further +1 bonus to damage rolls - although their armour class drops by 2 to represent the wild abandon with which they fight.
Nurkulah's mountains are very high - the peaks can reach 6000 metres. At such altitudes humans and demihumans become very weak. This results in an effective reduction in strength and constitution by 2 points, and a gradual tiring in combat which causes a -1 modifier to hit and damage after three rounds and a -2 modifer after five. The goblins do not feel these effects.