While most of the realm is ordinary earth and forests, several elements of the Shadow Realm are unique to it—or at least far more common than elsewhere. These hazards and landmarks are described below.
Doomsand. Similar in most ways to standard quicksand, doomsand follows the same rules for sinking and escaping. This ashen-gray slurry is infused with the nature of shadow, and it drains the resolve from those in its grasp. A creature that starts its turn in doomsand must succeed on a DC 12 Wisdom saving throw or become despondent (see Shadow Corruption below). When the creature finishes a long rest, it can repeat the saving throw, ending the effect on a success. Doomsand usually appears in marshes and swamps, or in deserts as fine dust.
Ebon Tides. Ebon tides are enormous waves of shadow mire, of crackling shadow matter—a temporary wave of arcane power pulsing through a region and unmaking the land. When they affect a region, use the effects of the ebon tide spell (see Chapter 4).
Hungry Gloom. Some areas of the Shadow Realm—or places in the mortal world where the barrier to the Shadow Realm is thin—develop hungry gloom. An area of hungry gloom appears particularly dark and grim, swallowing light. An area of light that overlaps hungry gloom has its illumination reduced by one step (bright light becomes dim, dim light becomes darkness). Darkvision can't improve the ambient light conditions in the area. Shadow-touched creatures (see Shadow Corruption below) can see in hungry gloom as if it were bright light.
Leaden Clouds. These dark, heavy clouds oppress the spirit of those beneath them, serving as a sort of psychic weight. Creatures under a leaden cloud of sorrow must succeed on a DC 12 Wisdom or Charisma saving throw to make an attack, cast a spell, or move at more than a standard walking pace (though they can still defend themselves normally). Certain items, such as emerald goblets (see Chapter 10), and spells, such as aid, calm emotions, enthrall, and lesser restoration, and even a barbarian's Rage ability negate the effects of leaden clouds.
Radiant Wells. This form of well resembles a beacon of light at the surface, though it swallows up anything thrown into it. A radiant well is a planar link to one of the celestial planes, and it sheds searing, bright daylight in a 60-foot radius around itself and up into the clouds. This makes them excellent landmarks for navigation, though their position can be shifted by ebon tides and terrain manipulation. Any creature entering a radiant well falls for 1 round and then is ejected upward at relatively high speed from another well within 2d20 miles (for evil creatures, this increases to 1d100 miles). The force of being ejected from the well propels a Small or smaller creature up about 30 feet before falling to the ground beside the well (potentially taking normal falling damage). Medium and Large creatures are pushed up about 15 feet, and Huge or larger creatures simply land at the edge of the well.
Particularly large or active radiant wells sometimes inflict radiant damage on evil-aligned creatures. These more active wells are sometimes used as nodes or portals to celestial planes by fey wizards and clerics.
Shadow Mire. Usually found along the shores of ponds, lakes, and streams, shadow mire is a concentration of pure shadow matter that has eaten away the soil, roots, and plants of a place and replaced them with a thin layer of viscous purple-black gloop. This resembles dark water and is indistinguishable from water at night—leaves and reeds may float on it, and it reflects moonlight normally. However, stepping into shadow mire generates an immediate, oversized wave that radiates from the creature entering the mire, knocking down all in its path. Any creatures within 30 feet, which are smaller than the creature stepping into the mire, must succeed on a DC 13 Strength (Athletics) or Dexterity (Acrobatics) saving throw or be knocked prone by the wave.
The creature in the center of the mire will be covered by the shadow mire as it rolls back to its point of origin, like the splash of an enormous raindrop. The creature must make a DC 13 Constitution saving throw or be knocked prone and unconscious.
Some wizards can distill or conjure pits of shadow mire (see spells in Chapter 4 and magic items in Chapter 10) and thus reshape a riverbed or undermine a bridge, for instance.
Witchlights and Will-o'-Wisps. The Shadow Realm is filled with lesser lights than that of the moons and stars, wandering along with typically inscrutable aims. A white glow shines in the distance, offering a path or a sign of habitation—or simply zipping through the deep woods. These are the tiny witchlights (see Tome of Beasts 1) and the larger will-o'-wisps, both of which create their own light. The witchlights are tiny shards of crystal, constructed creatures believed to have been made as friends, servants, and companions to the Ancients of shadow. Only relatively powerful wizards know how to make them, but many roam the Shadow Realm on their own.
Witchlights pursue their own purposes: guarding dangerous sites, helping travelers, seeking out old runestones, or gathering at certain seasons to dance and blink in unison. Others tag along with strangers for hours, perhaps driven by curiosity. Their appearance is well known, but their goals are often quite obscure. Some are friendly while others guide travelers astray, and a few of them serve as familiars to wizards and sorcerers among the shadow fey and shadow goblins.
Will-o'-wisps, their larger cousins, are generally malign and capable of more damage in combat. They lead travelers into doomsand or shadow mire and even use their attacks to sever boat lines or rope bridges.