The desert is nearly impassable. Obviously it’s plagued by some giant sandworm-like creatures, as well as its environmental hazards. Surely someone crosses it, though! You have desert caravans in your D&D world, right?

Whoever the caravan masters are – humans? halflings? dragonborn in 4e? – they need some way to fight off the sandworms, blue dragons, and other high-level desert creatures. With food and water so scarce, there’s no way that hundreds of defenseless creatures – walking meals – are going to make it alive across the wastes, even if they do make a practice of hiring PCs as guards.

Since D&D is a post-apocalyptic game, the caravanners may well have cobbled together a Jawa sandcrawler-type vehicle from the magical vehicles of previous ages. It’s all Mad Max scrap metal, giant tank treads and armor, but seamed with golden light and bolted with runes. The desert crawler must be armed with a weapon powerful enough to keep the giant monsters at bay. Solar power is the traditional technology of all-knowing progenitor cultures, so let’s give it a mirror cannon that focuses beams of radiant energy.

No magic engine has survived from the ancient empires, so the desert crawler is powered by slaves in treadmills. The slaves are mostly the orcs and elves who live on the desert’s border. The caravan is always looking to buy strong slaves, so if the PCs are defeated in the desert by any intelligent opponent, they may wake up in a treadmill themselves.

How do the PCs escape from the caravan? Straying from the caravan’s oasis-dotted route invites death from thirst and sandstorm. Falling behind will put the escapees in the midst of the swarm of landsharks who pick off stragglers. Traveling ahead? Possible, but only the caravan leader has a map of the route.

The best option is the classic swashbuckling approach: free the galley slaves, throw the slavers to the sharks, and become a privateer on the desert sea.

If, in D&D, superstition is always right, then cultural taboos are to be doubly respected. Many of the magical ills in the D&D universe arose because someone violated a taboo.

When someone violates a taboo, have them make a saving throw. If they fail, they may contract the curse appropriate to their crime.

cannibalism: If you eat of your own kind, you’re likely to contract a disease that causes your hair to fall out, your flesh to whiten, and your teeth to hunger for more human flesh. In the disease’s final stage, you become a ghoul, and you will spread your disease to those you kill. Let that be a lesson to you: if you’re stuck in a cave-in, the human should eat the elf corpse and vice versa.

murder of kin: The curse attendant on brother murdering brother is attested in one of the oldest sword and sorcery tales of all: the story of Kane, by Karl Edward Wagner. Just kidding. But seriously, kin killing should put you magically outside the pale of society. I’d say that someone who contracts the Kin-Killer’s Mark can’t recover healing surges by sleeping in a settlement, and takes damage, instead of healing, from clerical healing from allies. I wouldn’t be surprised if kin-killing were a necessary part of becoming a death knight, as well.

murder of guests: When you share food with someone, you enter a guest-host relationship in which violence is forbidden. Those who violate this rule are doomed to lose food’s sustaining powers: from now on, they can only sate their hunger with violence and betrayal – in other words, human blood. They become vampires. Consider also vampires’ inability to enter a house without permission: the vampire is constantly forced to enter an explicit guest relationship, and then betray it in a bloody feast, re-enacting the vampires’ initial betrayal of the guest meal.

bestiality: D&D is a world where every monster is half this and half that (or a third!) and it can’t all be the work of mad wizards. Obviously, in D&D, any mating can produce offspring: furthermore, I think that not only will the children be beast-men, but the guilty parents may take on bestial natures as well. This is especially common near the feywild, where every animal species’s nobility can take human form. However, not every satyr goat-herd has the excuse of living near the feywild.

incest: This taboo is most commonly violated by royalty, so much so that its visible effects are often called the King’s Curse. It not only enters the bloodline but affect the parents. The King’s Curse manifests as madness and cruelty. It also often causes extreme physical delicacy (a penalty to fortitude defense).