From Ardrana

The weakest of all genies, jann are native to the Prime Material Plane. (Jann is plural; janni is singular.) They are servants to other genie races and keepers of the wild, inhospitable reaches of the deserts. Some say that jann were created by powerful elemental creatures who hoped to circumvent the restriction preventing genies from granting wishes to other genies. Such was not the case, for the jann are as limited as their elemental cousins in this matter.

Jann look like statuesque Humans or half-Elves with handsome, noble features. Their flesh is the color of sand and earth, and (unlike djinn) they may pass unnoticed among mere mortals without attracting undue attention. Their eyes may be blue, green, brown, black, or something in between, but they often seem to flash like hot, colored sparks, lively and energetic.

Desert heat and windborne sand cannot harm the jann; their skin is very resilient. In battle, they wear a type of lamellar. For weapons, jann favor great scimitars and composite long bows.

Jann can travel freely to the Astral and Ethereal Planes. They can also visit the Planes of Water, Air, Fire, and Earth, and they are often found on these elemental planes as solitary tourists, or in the service of another genie race.

Jann value their privacy and safety. They favor the forlorn deserts of Ardrana, from the inhospitable deep deserts to lush oases. They are nomads, though they move their camps less frequently than mortals, and they do maintain some permanent settlements. Their tribes travel with herds of camels, goats, and sheep between good grasslands and oases. As a people, they are the emblem of the virtues of the desert. They are strong, brave, and valiant. They are proud and brook no insult or impropriety, and see that injuries are repaid in kind. By the same token, they are hospitable to travelers and strangers, and treat them with honor and respect when they are among them, expecting the same treatment in return.

On the move, jann live in large, brightly-colored tents with their families. Male and female jann are treated equally, and a successful male or female may have a number of spouses. Traditionally a married male remains within (or at least near) his family's tent. A married female lives with her first spouse's family until she marries again, at which time a neutral location for her tent is chosen. Whenever a family outgrows a single tent, children move into their own quarters.

Jann also maintain permanent settlements in hidden oases, windswept holy sites, and deserted cities. Tents are common in such permanent locations, but the jann also build elegant, sweeping structures for communal use. Such structures might include a mosque, bathhouse (with quarters for visiting marids), smokehouse (with similar quarters so that efreet are comfortable), and occasionally an audience chamber for the jann's leaders.

Jann are on excellent terms with djinn, and in an emergency the jann will send a messenger to the Elemental Plane of Air to request reinforcements. The jann tolerate efreet, who tend to be foul-tempered and overbearing, taking advantage of any hospitality offered while offering little in return. Similarly, jann tolerate dao, but often with a thinly veiled hostility, because jann are sometimes captives in the dao's native plane. The marids are treated as the royalty they consider themselves to be, but their visits to the water-stricken deserts are infrequent.

Note: Jann originally appeared in this form in the Al-Qadim: Land of Fate for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.