The index of TSR's immortal volume Fiend Folio lists the creator of the xvart as one Cricky Hitchcock. But the creature's name (if not the spelling) will be familiar to fans of the novels of Alan Garner, and speakers of Scandinavian languages.

Where did the blue-skinned goblins found in Fiend Folio (and MC14, its Advanced Dungeons and Dragons Second Edition counterpart), and rampaging in such numbers through the Baldur's Gate games, spring from?

The answer lies in the same place as the origin of the drow. The word is simply an excessively science-fictional spelling of 'svart', which is the word for 'black' in many Scandinavian languages. The German word schwarz is from the same root, as is the obsolete English word swart (from which swarthy derives). In Norse mythology, the elves (alfar) are divided into two classes. The Liosalfar - light elves, Ljusalfar in modern Swedish - are said to follow Frey, head of the Vanir, and an astral deity. The dark elves, or Svartalfar, instead follow (according to some sources) Wieland/Wayland, the smith-god, who has a clearly cthonic aspect. There is also some confusion in this respect with the dwarves (dvergar, from which AD&D gets its 'derro' and 'duergar'), and with the trolls (trow/drow in old Scottish dialects).

Milton makes reference to a swart fairy, as a synonym for a spirit of ill-omen, in Comus. My sources for dark-elf nomenclature are a little patchy after this, but we hit a definite reference in the novels The Weirdstone of Brisingamen and The Moon of Gomrath, by British fantasy author Alan Garner. These books, drawing heavily (too heavily, some might say) on Celtic and Nordic legend, feature a race of malignant goblin-like creatures, fitting almost exactly the Fiend Folio description, called svart-alfar, or svarts for short.

The established society of xvart(s) in their AD&D incarnation has little if anything to do with their Norse heritage. Stripped of interesting mythic background, they become yet another addition to the ranks of 'goblinoids'. Their blue skin does not really distinguish them significantly from the existing orcs, goblins, kobolds (before the Third Edition reinforced kobolds' reptilian nature), hobgoblins, bugbears, nilbogs and other bugaboos. In the official AD&D canon, they were initially restricted to the World of Greyhawk setting, where they worshipped a cruel god called Raxivort. However, their appearance in the original Baldur's Gate computer game confirmed many players' existing use of them in the Forgotten Realms setting. So far as I am aware, no statement has appeared about the religion of xvart on Toril.

To confuse your AD&D players, I recommend referring to drow as svartalfar (in my Planescape campaign I gave svartalfar a contextual spin meaning something like 'elf of colour') and to xvart as 'swart-fairies', or even 'drow' or 'troll'. Their initial tactics may be amusingly wrong. And play with their minds on the religion front as well. Those they worship the usual AD&D drow goddess, Lolth, or the Forgotten Realms 'good' drow goddess, Eilistraee, or Wayland, or even Loki? And what of the xvart?