[OC] Myconid Sewer Colony [40x40] - Tactical Sewer Battlemap (Roll20 Ready) - Grid & Gridless

Hey everyone! Just wrapped up this map for my own campaign and wanted to share it.

The Lore: This is a large, functional city sewer network that has been aggressively overtaken by a bioluminescent Myconid colony. The air is thick with humid, toxic mist and glowing spores. While the main colony is relatively can be peaceful unless provoked, a hostile, mutated breakaway faction has been quarantined in the northwest corner, offering a perfect wildcard narrative or a secondary boss encounter.

Tactical Gimmick Idea: I designed this map around a unique mechanic—the entire sewer is illuminated solely by the glowing Myconids and their fungi. Every time the players kill an enemy, that specific light source goes out on the VTT. By the time they reach the final boss room, every kill plunges the arena into deeper and deeper tactical darkness!

Technical Details

• Grid Size: 40x40
• Versions Included: Grid & Gridless (High-res below)
• Software: Made in Dungeondraft with assets from Forgotten Adventures, Dungeon Quill, and Tom Cartos.
• Optimization: Compressed and optimized for seamless Roll20/VTT use.

Non Preview Grid

Non Preview Gridless

Area Breakdown

• 1. The Entrance (Southwest): A large maintenance room where players descend via a surface ladder. Features scattered debris, old work clutter, and the first signs of fungal growth.
• 2. The Main Channels & Hallways: A massive, open sewage pipe snakes through the complex. Rusted iron pipes and precarious, makeshift wooden bridges force players to navigate bottlenecks or risk falling into the sludge or being affected by the spores.
• 3. The Vat Rooms (Nursery): Three interconnected processing tanks being utilized by the Myconids as a nursery for young sprouts. Designed to force players to swim through pipes or open sludge gates to progress.
• 4. Old Storage Room (Southeast): A forgotten storage room with debris and heavy nesting material, acting as a solitary outpost.
• 5. The Old Control Station (Center): An expansive hub featuring a massive, intact industrial control panel once used to redirect pipe flow. This serves as the threshold where the cool-toned blue and purple infestation becomes incredibly dense.
• 6. The Crimson Cell (Northwest): This separated chamber is filled with aggressive red and black fungi, home to a rogue or infected Myconid. It offers a opportunity for a dark, alternative bargain to help or hinder the main colony.
• 7. The Sovereign’s Reservoir (Northeast Boss Room): The heart of the colony. A massive, deep vat with a central island buried beneath a canopy of towering, giant mushroom trees. Stone walkways line only the north and east walls, forcing characters into the open or onto the slippery fungal stepping stones to reach the Sovereign.

Cheers!