The Hidden Island is normally avoided by ships. It lays in the deep sea, surrounded by a pod of kraken. The island itself has two buildings on it. Both are submerged just a few feet under the water, so are a bit of a navigation hazard, especially during storms.
The two buildings are ancient temples. Each [...]

It’ll take a rogue to or elf character to notice a hidden door in a back alley down near the docks.
Opening it reveals a lasciviously appointed ante-chamber. Directly across from the entrance is another door – heavily barred and spell warded. Next to it is posted a tattered piece of parchment that says “Cant [...]

The Runic Fellowship is a group adventurers that have been working together for many years.
Vyecheslav, male human Drd11: CR 11; Size M (5 ft., 2 in. tall); HD 11d8; hp 58; Init +1 (+1 Dex); Spd 30 ft.; AC 11 (+1 Dex); Attack +9/+4 melee, or +9/+4 ranged; SV Fort +7, Ref +4, Will +10; [...]

This is an action comedy. The story is about a stressed exorcist hiding a dark secret. It takes place in a pocket universe. A magical artifact plays an important role.

The story is about a bandit and a peasant. It starts in a steam-driven fiefdom in a magical dimension.

The story begins with an invasion of [...]

The pirates ship is a converted merchantman crewed by 30 pirates. A pair of oars on each side gives it maneuverability against the wind.
Pirate Leader
Name Green-Eye Razicad, the Dwarven Pirate Alignment: Neutral evil Gender: Male Race: Dwarf Height: 4′ 2; Weight: 185 lbs Strength: 20 (+5) Dexterity: 14 (+2) Constitution: 17 (+3) Intelligence: 10 (+0) [...]

Desolate areas are wild caves and tunnels that are not settled and generally do not support much in the way of wildlife or monsters. Much of the Lowerdark is desolate.
Aboleth
Aboleth slaver brood
Annihilator
Avolakia
Behir
Beholder
Beholderkin (deathkiss or gouger)
Bodak
Cloaker mob
Cloaker, shadowcloak elder
Cockroach, giant
Deepspawn brood
Delver
Desmodu
Dragon, mature adult deep
Dragon, mature adult copper
Dragon, very old black
Dragon, mature adult red
Dragon, mature adult shadow
Drow [...]

Lowerdark wilderness areas are wild caves and tunnels that are not settled but still support significant wildlife or monsters.
Aboleth
Aboleth slaver brood
Annihilator
Avolakia
Behir
Beholder
Beholderkin (deathkiss or gouger)
Bodak
Cildabrin
Cloaker mob
Cloaker, shadowcloak elder
Cockroach, giant
Desmodu
Delver
Dragon, adult deep
Dragon, adult copper
Dragon, old black
Dragon, adult red
Dragon, adult shadow
Drider
Drider, vampire
Drow patrol
Duergar raiders
Deepspawn & spawn
Earth Glider
Fiendwurm
Fomorian
Giant, stone
Gloura
Grimlock hunters
Gray render
Hound of the gloom
Illithidae (any)
Knell beetle
Kuo-toa war party
Lurker
Lurking strangler
Maur
Mind [...]

Wilderness areas in the Middledark are wild caves and tunnels that are not settled but still support significant wildlife and monsters.
All-consuming hunger
Arcane ooze
Bat, deep (sinister)
Barghest
Behir
Beholder
Bodak
Chitine hunters
Cildabrin
Cloaker
Cockroach, giant
Deepspawn and spawn
Delver
Derro bandits
Destrachan
Devourer
Dragon, young adult deep
Dragon, adult black
Dragon, young adult shadow
Drider
Drider, vampire
Drow patrol
Drow slavers
Duergar marauders
Earth Glider
Fomorian
Foulwing
Giant, stone
Gibbering mouther
Gloura
Grimlock hunters
Hook horror
Hound of the gloom
Ineffable horror
Kuo-toa patrol
Knell beetle, lesser
Lurker
Lurking strangler
Maur
Metalmaster
Mind [...]

Settled areas feature colossal caverns that can be miles on a side, a number of small villages and vaults no more than a day or two travel from each other, and some tunnel patrols from nearby cities or fortresses. Patrols are most often Drow, Illithid Thralls, Duergar, or Derro.
All-consuming hunger
Barghest
Bat, deep (sinister)
Behir
Chitine hunters
Cildabrin
Cloaker
Deepspawn & spawn
Derro [...]

Possible list of encounters in the Frontier areas of the Underdark. Frontier areas are lightly settled tunnels or caves, but communities are small and far apart, usually separated by miles of tunnels. Occasional larger forts maybe present to give warning to larger settlements in the distance.
Abishai, black
Ankheg
Baphotaur
Bat, deep
Baneguard
Beholder, gauth
Bodak
Bugbear band (hunters, scouts, family group)
Chitine hunters
Cildabrin
Cloaker
Cockroach, [...]