We already saw several underground danger spots in the city. Neverdeath Cemetery, the dungeons of Castle Never, and of course the Chasm. But there are even more beyond those. The Mintarn mercs usually stay on the surface, so every one of these places can be considered “dungeon-like”.

Shattered Sewers

Neverwinter had an extensive sewer system that’s still largely ruined. It makes for a great way to move about the entire city undetected, but it’s hazardous to navigate and filled with both monsters and other people who don’t want to be discovered.

Kraken Tunnels

This is an underground complex with a floor plan that vaguely resembles an octopus. It used to be the former headquarters of the Kraken Society, a criminal syndicate specializing in slavery. Now it’s the headquarters for the Nashers faction of the Sons of Alagondar.

The complex is build right above an underground canal that links to the sea, and this canal is the home of an actual kraken. The Spellplague reduced the monster to bestial intelligence. The Society used to feed it and keep it as a guardian beast, and the Nashers have continued the practice. The complex has several floor openings through which the creature can attack intruders.

The kraken was trained by the Society to recognize anyone bearing an amulet with its symbol as a friend - it attacks all who don’t have this amulet on them. The Nashers know this and carry Kraken Society amulets with them when inside the complex.

There’s a tunnel here that links the Kraken Tunnels to the Dead Rats’ HQ through the sewers, which the Nashers use to talk and trade with them. The Rats don’t yet know the trick to avoiding the Kraken, but it’s just a matter of time until they find out and attempt to take over.

It’s possible the Nashers might end up releasing the kraken into the river or the docks as a sort of weapon of mass destruction if they become desperate enough. The aboleths could also try to get to it in order to search its mind for secrets from back when it was sapient.

Dead Rat Hole

This is a section of the sewers that has been taken over by the Neverwinter chapter of the Dead Rats. It’s marked with gang signs gouged into the sewer walls, and packed with both loot and trash collected by the gangers. Their leader, Rsolk, holds court at a set of caves near the shores of Blacklake. There’s a trap here that can let the waters of the lake in and “flush” the whole complex.

These Dead Rats are not familiar with the Dead Rat Deserter PC, contrary to what I thought before. Looks like word hasn’t got to them yet. A bold Deserter might try to infiltrate the gang and perhaps even challenge Rsolk for leadership. This starts as a one-on-one duel but turns into a standard mass fight once he’s bloodied. And of course he flushes the lair if it looks like his side will lose.

Tunnels and Trenches

The sewers around the Chasm area are partly collapsed, forming trenches where the street above was destroyed and tunnels where it hasn’t. This and the influx of non-sapient monsters provides good cover for the AbSov’s smarter agents to infiltrate the River District or to escape the city and head to Helm’s Hold and other places.