Wandering monsters are infrequent in the sparse city ruins; check hourly (1 on a 1d6) and once overnight if the group camps in a hex. Note that some of the set locations have rules that override the normal wandering monster results (example: Wind Walkers are common near the Blue Obelisk, a Mi-Go patrol might be encountered in the hexes surrounding the Tower of Pain, a Star Demon hunts near the Palladium).
The city is loosely divided into 4 zones - zone 1 is the southern end of the city near the Well of Woe, the areas closest to Trade Town and most picked over by previous explorers. Zone 2 is below the Great Glacier that cuts the city in half. Zone 3 is everything north of the Glacier. (I may put together a simple map color coding the zones for easy visual reference).
Coming soon - populating hex contents!
4 Zombie or Skeleton
6 Giant Rat
1 NPC Party
4 Berserker Stage 2
6 Giant Shrew
1 NPC Party
2 Berserker Stage 3
4 Undead (wraith or spectre)
6 Giant Furry Snake
1 Polar Bear
2 Giant Furry Snake
3 Wind Walker
Notes on Monsters:
Ape-Men of the Black City
These ferocious hominids will have their own bestiary article.
Northmen raiders that have chosen to kill and loot other explorers. These vicious robbers will hide their identities and ensure that no survivors return to Trade Town.
Berserker, Berserker Stage 2, Berserker Stage 3
Berserkers have their own bestiary article describing the different stages of Worm Madness.
The baleful influence of the Dark Goddess ensures that sentient beings that die in the dungeons (level 2 and below) rise as hungry ghouls unless properly buried. The Neanderthals cremate their dead, whereas the Morlocks eat their dead. Most extant ghouls will be dead Vikings that clamber out of the dungeons looking for food. Ghouls that don't consistently eat flesh degrade over time into zombies and ultimately skeletons; their bodies and intelligence withers but their undead spark lingers.
Giant Furry Snake
The Thule Snake is a giant poisonous snake covered with white fur. They are amphibious monsters that live near the coasts and typically feed on marine mammals; occasionally they slither into the city seeking giant rodents that have escaped the dungeons.
Giant Rats / Giant Shrews
These oversized rodents have escaped from the fecund level 2, the Warrens of Decay, a vast cavern full of oversized vermin.
In Viking terms, the noble is a Hersir with a group of loyal house guards (huskarlar). While Hersar often sponsor crews that come to Thule, it's unusual to find one performing his own adventuring, and this figure will be well known. (In BX terms, the Hersir will be level 3+, he'll have a level 2 guardsman and 1-10 level 1 huskarlar).
Generated per the standard rules, flavored as Vikings.
These unusual monsters are colored white for the arctic terrain (like a mix of snow owl and polar bear).
Polar bears are a constant threat across the Thule archipelago, and are the most dangerous natural predator.
Skeletons and Zombies
These are degraded ghouls that waste away into unintelligent lower forms of undead from ghouls (as opposed to being created via the animate dead spell). They're still compelled to kill and eat the living when encountered, it just doesn't restore or sustain them any longer.
Traders consist of 3-18 level 1 fighters, with 1-4 mules, engaged primarily in excavation and recovery of artifacts - they'll be armed, and will also have shovels, picks, and digging equipment. Like everyone else, they've arrived in Trade Town via longship and will be dressed appropriately.
A group of veterans is a mix of 2-12 fighters of levels 1-3, per the BX rules. Unlike traders, these Vikings explore the ruins seeking monster lairs and creatures to fight and loot.
Wight, Wraith and Specter
These undead may be the ancient remnants of one of the city's earlier races. Roll a 10 sided die:
1 An ancient Grey (will have maximum hit points for hit die)
These invisible demons of the northern wind blow along the icy glaciers, scouring flesh off the bone.
The Yeti live in the northern mountains but occasionally follow the glaciers down into the lowlands looking for food.