Large swathes of the western Dar’Spelun Slugmarsh are covered in unnaturally dark trees that fully extend over the bog. Many creatures don’t notice the abnormality; only those that make a DC 19 Perception check see that what they walk upon is heavily matted moss covered in dirt, all suspended on the roots of numerous trees! Underneath the “ground” is a 10 to 15 foot drop into murky, disgusting bog water, filled with rotting matter and worse (DC 17 Swim check).
Strange smells that pique your curiosity but defy identification seem to emanate from everywhere and nowhere all at once as you head deeper into these subterranean groves. Skeletal trees are everywhere, their roots disappearing beneath furred moss of greens, browns, and sooty blacks. Despite their lack of foliage, the ebony and dark grey bark are so dense that they block out any sight of the roof of the cavern.
All of the ground in the Tangleroot Forest is considered difficult terrain. Every minute outside of combat or every movement greater than a 5-foot step during combat requires a DC 10 Acrobatics check; on a failure, a creature gets their feet caught in troublesome roots. Any creature weighing in total more than 100 pounds increases the DC of this check by +2, and a creature weighing more than 200 pounds increases the DC of this check by another +2 and a creature weighing 300 pounds or more increases the check by another +2 (to DC 16). Creatures with a climb speed and creatures of a size of Tiny or less are immune to this effect.
Once affected by the ground of the Tangleroot Forest, a creature cannot take any movement until freed.
Creatures that snag their feet on the floor of the Tangleroot Forest must succeed on a CMB, Reflex, or Escape Artist check as a swift action to free themselves (whichever is best) against the same DC as the Acrobatics check + 5. Attempting this as a move action reduces the DC of the check to free themselves by -5. Failure on a check to free itself knocks a creature prone.
During combat the danger of stepping into or through the floor of the Tangleroot Forest increases dramatically. Movement of any kind in between squares requires an Acrobatics check as described above (DC 10, 12, 14 or 16 depending on a creature’s weight). Additionally, when a creature reaches the end of any movement during a combat round in the Tangleroot Forest, there is a chance the ground they stop on breaks beneath them! Creatures of Tiny size are immune to this effect, but there is a 5% chance for each size category larger than Tiny that a creature falls through the roots and into the dirty bog water below (5% Small, 10% Medium, 15% Large, and so on).
Monsters of many kinds wander the Dar’Spelun Slugmarsh (indeed—grick swim all over the bog underneath the Underworld groves), but the Tangleroot Forest is almost exclusively ruled over by crazed fey. For the most part, they are not much of a danger. They do constitute a threat, however—PCs that camp on the “floor” of the Tangleroot Forest may fall into the bog underneath, the squares they occupy undermined by the mischievous fey (25% chance). Other dangers like the souls of those that have died here and angry, intelligent, territorial plants stalk the Tangleroot Forest, and many who cross the region waste no time in doing so lest they draw their unwelcome attentions. Whatever the creature
d100 Creatures Encounters
1-22 6 sprites, 2d4 nixie, 1d4 grig
23-46 2d6 quickling
47-64 1d4+2 redcaps
65-82 1d4 will-o’-wisps
82-96 1d4 quickwood
91-100 carrion crawler [see this week's Statblock Sunday!]