Djinni are one of the four genie races of the multiverse of Dungeons & Dragons, being associated with the Elemental force of Air. Like all genies, they are natives of either the Elemental Planes, specifically the Plane of Air, or the Elemental Chaos, depending on whether you look at them from the perspective of the Great Wheel or the World Axis.
Djinn are an arrogant breed, looking down on all races incapable of natural flight, but not a malicious one; despite their arrogance, they have a fundamental respect for the notion of freedom, like most airy elementals, and are generally content to live and let live. On the Plane of Air, they dwell in isolated freeholds made of solidified clouds or floating islands of earth. Such a freehold consists of 6d10 "commoner" djinni, often with about one-third that number in janni, as well as a staff of lesser air elementals that function as servants, soldiers and laborers. The leader of a freehold typically calls itself by an Islamic noble title, and the loose society of the djinni centers itself around the more powerful members of their kind, called "Caliphs"; each caliph rules over all djinn estates within two days travel, and ultimately they report to the Great Caliph, the supreme ruler of their race who dwells in the Citadel of Ice and Steel. Such is the power of this Great Caliph that even the fey races indigenous to the Plane of Air offer the position respect or outright serve the current incumbent. Rumor has that even Sardior, the god of the Gem Dragons, has been known to visit the Great Caliph of the Djinn.
Perhaps due to their arrogance, the djinn are frequently at war. On the Plane of Air, they regularly battle Cloud Giants, Storm Giants, and other airy elementals. But their bitterest and most long-lasting feud is with a fellow genie race - not the Dao of the Plane of Earth, as you might expect (perhaps due to the fact each finds the other's environment nauseating if not terrifying), but the Efreeti. This ultimately stems from their opposing personalities; though the djinn are an arrogant race, they respect individual achievement and hate slavery - djinn have servants, yes, but in the form of retainers who enjoy their position and respected for their aid. In comparison, the efreeti are tyrannical, authoritarian, and love to enslave others. It's not unheard of for particularly driven djinni to undertake crusades or raids against efreeti or dao to free their slaves and embarrass them, and they will cooperate in any attempt to embarrass or thwart their enemies.
Djinni possess a number of magical abilities, mostly relating to illusions or low-level transmutations. Their iconic power is their ability to summon a whirlwind as a personal steed to carry them at speeds far faster than they can fly. These genies look like exceedingly tall, well-muscled men and women, always possessing attractive, noble-looking features. Their skin color ranges from pale blue to the more common olive-brown and dark tan of desert natives. Their eyes are usually brown, but there are also blue-eyed djinn, who are believed to be marked by Fate for great actions. (Blue also suggests increased powers of the evil eye, however.) Djinn dress in airy, shimmering silks, which are designed for comfort as well as to flaunt their musculature.
Uniquely amongst the four "true" genies, djinn can't grant wishes at all - only the more powerful "Noble Djinni" has this ability, and they can only grant three wishes to a single individual in that individual's life.
Proud, sensuous genies from the Elemental Plane of Air, the djinn are attractive, tall, well-muscled humanoids with blue skin and dark eyes. They dress in airy, shimmering silks, designed as much for comfort as to flaunt their musculature.
Airy Aesthetes: Djinn rule floating islands of clouds tuff covered with enormous pavilions, or topped with wondrous buildings, courtyards, fountains, and gardens. Creatures of comfort and ease, djinn enjoy succulent fruits, pungent wines, fine perfumes, and beautiful music. Djinn are known for their sense of mischief and their favorable attitude toward mortals. Among genies, djinn deal coolly with efreet and marids, whom they view as haughty. They openly despise dao and strike against them with little provocation.
Masters of the Wind: Masters of the air, the djinn ride powerful whirlwinds that they create and direct on a whim, and which can even carry passengers. Creatures that stand against a djinni are assaulted by wind and thunder, even as the djinni spins away on that wind if outmatched in combat. When a djinni flies, its lower body transforms into a column of swirling air.
Accepting Servitors: The djinn believe that servitude is a matter of fate, and that no being can contest the hand of fate. As a result, of all the genies, djinn are the ones most amenable to servitude, though they never enjoy it. Djinn treat their slaves more like servants deserving of kindness and protection, and they part with them reluctantly. A mortal who desires the brief service of a djinni can entreat it with fine gifts, or use flattery to bribe it into compliance. Powerful wizards are able to forgo such niceties, however, if they can summon, bind into service, or imprison a djinni using magic. Long-term service displeases a djinni, and imprisonment is inexcusable. Djin11 resent the cruel wizards that have imprisoned their" kind in bottles, iron flasks, and wind instruments throughout the ages. Betrayal, particularly by a mortal whom a djinni trusted, is a vile deed that only deadly vengeance can amend.
Djinni were once one of the great powers of the World Axis, with an unparalleled ability to shape chaos-stuff into whatever they desired. Mighty mage-artisans, they were supposedly born at the spot in the Elemental Chaos where the first cloud took shape, growing until it spread for miles in all direction. Here, the djinni came into being, and created the First City; a sprawling work of living art. They were arguably the most society of all the elemental races; a marvel of soaring inspiration, intellect, and creative power, free of the warlike natures of efreeti or titans. They were the original inventors of al-Buraj, the mystical art that is used to help navigate the Elemental Chaos.
Unfortunately, they are now a shattered, broken people; whilst they cling to the attitudes of haughty nobles, it's a desperate attempt to deny how far they fell. The djinni made the unwise decision to fight the Dawn War on the side of the Primordials - most likely because they feared that the gods would strip them of their ability to shape and mold reality as they saw fit. That became a self-fulfilling prophecy; when they lost, the gods punished the djinni by sealing their mightiest leaders into physical vessels, and stripping all who remained free of significant portions of their power.
So broken are the modern djinni that they have abandoned their former holdings, including the magnificent cloud fortresses that their noble caliphs once called home. As they see it, there is little purporse in rebuilding their society as it once was if they cannot make it exactly as it was. They now eke out existences as either solitary nomads or small clans, constantly struggling to find a way to free the imprisoned caliphs or restore their former power; this desperation to shake off the yoke of their shameful punishment and reclaim even an echo of their lost glory leaves them a grim race.
Alongside their hated rivals, the Efreeti, djinni are the oldest of the four genie races in D&D metalore, having debuted in the original "white box" for Dungeons & Dragons back in 1974. They were converted to Advanced Dungeons & Dragons 1e in the original Monster Manual, and to BECMI in the Basic Set.
They first made their appearance in AD&D 2e under the "genie" heading in the Monstrous Compendium Volume One, which was then reprinted and in the Monstrous Manual. The noble djinni and the Great Caliph of the djinn appeared for the Al-Qadim setting in the Monstrous Compendium Al-Qadim Appendix. The djinn also appeared in this setting under the header "Genie of Zakhara" in the Land of Fate boxed set.
In Dungeons & Dragons 4th Edition, however, it lost that spot, and wouldn't appear until the Monster Manual 2. The race's lore would be fleshed out in the Elemental Chaos splatbook "Secrets of the Plane Below".