Campaign Idea: Tunnel Warriors

[PeterSmith]

So here's the setting: The players are all survivors in an underground network of tunnels. It's their job to patrol the tunnels and fight off any invading monstrosities that they come across. They were born and raised in this dark realm, never knowing the light of the surface. All they know is the dark and the things that crawl within. There are larger caverns where settlements exist, and the players patrol these tunnels to make sure that traffic between the settlements can flow safely to ensure the sharing of resources. In particular the glowing ichor that flows through the stones that powers the settlements and sustains the survivor's life force.

But here's the twist: The players aren't actually underground. Not in the traditional sense, anyway. They're ACTUALLY the immune system of a giant rock creature, and they've been fighting off bacteria and viruses the whole time. The 'settlements' are just their host's 'organs' in a sense, and the flowing ichor is their host's blood.

With this in mind, you can start to imagine some of the fascinating and terrifying things the players would experience. Their settlements would be able to completely lock down at a moment's notice, down to the last house. They might have settlement-wide defense systems that could 'flush out' invaders. Different monstrosities would require different weapons and tactics thanks to the defenses they've naturally developed over time. Different people in the settlements would have different jobs, such as construction/repair, transport, possibly even 'making' new defenders depending on how you want to flavor this.

Really this is just a fancy reskin of Cells at Work!, but with a darker tone and the added fun that you don't have to explain the actual setting to your players off the bat. You can let them figure it out as they have more encounters and start to make the connections on their own.

[Brookshw]

So what overall conflict or theme do you see for this campaign? Exploration/mystery to understand their world? Some kind of BBEG?