Ildirs is a flatworld, with a radius of some 6,000 kilometers. It is tidally locked (it always turns the same side toward it) with the sun, and as such its' two sides feature very different kinds of life. The planet spins around its' axis slowly (completes a rotation in 1200 standard days), as this hasn't got any effect on the surface, the inhabitants hadn't even discovered this. Ildirs has got one moon with normal circulation.
The atmosphere is standard on the top, easily breathable by most civilizations, on the backside all the gases in the atmosphere have long since liquified.
The planet is quite flat, the only major mountain is the spike standing in the exact center of the world (height 10 kilometers), the other areas are merely hills compared to this.
Since the planet is so far from the sun, the topside doesn't get very hot. In fact, its' weather is regarded as one of the most pleasant known to spacefarers, the temperature is an uniform 27 throughout the year, the rains are very light and the lack of big ocean areas precludes strong winds. The prevalent terrain type is rainforest, though there are areas of hills and some deserts.
The backside is quite different, temperature there is so close to absolute zero that all gases have solidified. There are hundreds of thousands of gigantic icicles all pointing away from the sun. The backside hasn't been explored but very briefly and from the safety of a ship.
The top side features a complete, if a bit slow-evolved ecosystem. Most of the plants there are bright red or purple in color, as to better capture the light from the sun. And there hasn't been any need for the reptiloid/amphibian lifeforms to step away from the throne, birds are non-existent and mammals occupy only a small support role.
The vast forests covering most of the world are an eerie experience for the traveller for the most part they are silent and instead of birds there are large butterflies swooning about in the sunshine. Sometimes an explorer can spot a rare winged frog (very poisonous) or become the victim of an ignorant spider-killer tortoise (who leap on the spiders from the trees), there are also many other forms of jurassic life never before seen on other planets. There aren't, however, any standard-issue dinosaurs found on Ildris, the creatures only rarely attain sizes in excess of 2 meters. Another group of animals mysteriously missing are the fish, they have been completely replaced by amphibians in the few lakes and rivers.
On the clearings in the jungle lives a race calling themselves the Njigra, commonly thought as black-skinned elves. Each clearing (size 2-10 square kilometers) supports a single family of these humanoids, they are very warlike, and regard any creature not from their tribe an enemy and a potential meal (foreigners only, they aren't cannibals). Since the clearings are separated by vast tracts of jungle it wouldn't be very common to have huge wars, but the Njigra have bred a species who can carry them aerially. This Ymbla, or jet-frog, is a peculiar creature and the elves constantly hone their skills in aerial warfare. Battles are fought high over the surface and the casualty rates in these fights are high (most projectiles are coated with a variety of poisons). However, the wars aren't an all-for-all affair, rather the Njigrae practice a fine art of diplomacy, where treaties can last from a few minutes to decades. And the wars are always fought 'gentlemanly', away from the villages and never endangering the innocent (especially females and the young).
The other sentient race on the topside are the amphibian Tasloi, who rule the rainforests around the biggest lakes. The Njigrae hate them thoroughly but have no effective means to fight with them (the tasloi keep to the ground all the time, and are as much familiar with the myriads of poisons as the elves themselves). The tasloi have a planetwide kingdom, ruled much like the Aztec nation: lots of gold and jewels, voluntary sacrifices, priests rule the whole kingdom, most of the skills used in building the large ziggurat-towns have been forgotten, mentions of spacefarers in legends. These towns are immense in size, probably the some of the biggest structures built by normal-sized humanoids, each city can easily accommodate 20,000 (over 100,000 when crowded) tasloi. Their god-king lives in a palace in the midpoint of the kingdom, this palace is built of black marble (the other ziggurats are of more 'mundane' stones) and every ceiling is lined with gold. Gold is very abundant in the jungle-regions of Ildris, and tasloi have once had far reaching mines under the nearby hills, nowadays they are largely deserted. The tasloi worship an obscure pantheon of diverse deities (Glu'kk the Scribe whose priests double as historians, Mna'gt whose priests alter all history according to their own whims), who apparently all require constant sacrifices.
There's a single spelljammer outpost on Ildris, this Whitehold consisting nowadays of perhaps twenty buildings, was founded by a priest of Mystara from Toril some thirty years ago. This patriarch laid down the laws that every visitor on the planet must obey or be expatriated very quickly: no aid whatsoever is to be given to a Njigra-tribe, no animals are to be released into the jungles, the Tasloi shan't be pestered (the last expedition was eaten). These laws sound pretty harsh, and many have thought that by disobeying them they could end the wars on Ildris quickly. The patriarch died three years ago, before his death he had gained quite a big congregation that is carrying on with his work. There are perhaps twenty ships permanently stationed to Ildris, and usually there's at least a few outsiders on vacation here. The clearing where Whitehold stands is surrounded with a broad moat, which contains a large number of crocks and water snakes. This is used both to protect the travellers from Njigrae (who seem to have difficulties in honoring any treaties with foreigners) and to prevent any animals from invading the jungles (not that they'd have a high life expectancies there, but the jammers have learned their lesson from the Marinas-disaster). Most of the NPCs stationed on Ildris are persons of a religious persuasion who are trying to show the Njigrae the advantages in taking up religion instead of spear. So far they have been totally unsuccessful in their attempts, their tries aren't helped by the fact that most priests won't get their full allotment of spells on Ildris. And this is a fact that has brought the normally not very close priesthood into amiably working with each other. With the tasloi isn't much contact, they live so far from the Whitehold and have responded violently to every attempt to build a base near them / explore their dwellings. Neither race has shown any particular interest in spelljamming, but the tasloan legends are full of stories with blue giants in sky chariots (apparently arcane who gave up with these creatures probably due to the bloodthirst).
The darkside is a totally alien environment for all travellers. But it is not totally devoid of life. Some of the largest **jpuikko** have been hollowed out and are inhabited by the hateful Zalathi, the ice goblins. They spend centuries in hibernation, but when an unfortunate ship or a kindori-sized animal comes too close to their home, they set forth in their coneshaped ice-ship to capture them (treat the **jp** as a 100- ton ship equipped with a piercing ram) at amazing speed (SR: 10 for short bursts, this is the fastest ship known). The ships then return to the planet using some sort of ropes. The darkside hasn't been explored at all, the few crews trying that have either returned with severe frostbites or fallen victims to these iceships. And it really is improbable that there would be anything found among the **jpuikko**.
A priest runs away from the Whitehold and joins a tribe. His bosses are eager enough to get him back to pay the PCs a handsome reward.
A Njigra-tribe tries to gain the upper hand in a particularly nasty war by trying to capture the PCs ship. They succeed and the PCs are given a creaking damselfly to get their own ship back.
The Rourke's Rift scenario where the Njigrae storm the Whitehold en masse.
A new priest of Cheslor hires the PCs to accompany him on a 'conquistading' trip to the Tasloi. When it doesn't go so well, the PCs are polymorphed into Tasloi and sent over to investigate the cities.
The PCs discover the uppermost stories of Tasloan ziggurats to be space ships, their engines eating gold. 40 ton ships made of stone, lousy maneuverability (E), quite slow (SR: 2), no weapons usable in space. However, the tasloi start approaching all manner of travellers willing to pay absurd amounts of gold for viable weapons.
The Tasloan gods return, and they _aren't_ the standard issue Arcane, but evil in nature. This would be a good followup to the previous idea, perhaps discovering the ziggurat-tops' nature was some sort of a cosmic test. And the tasloi would have soon dwindled into oblivion without the PCs' aid...
