Kobolds Are People Too: A Reverse Dungeon

[BootStrapTommy]

I'd suggest a gander at the Birthright setting from 2E (and it has an online 3.5 update wiki). Mostly by looking at system to manage lands, fortifications, troops, and leadership functions. The other mechanics and all the fluff should probably be ignored (though special bloodlines from dragons instead of gods could be fun) and all would need major adjustment but it would give you a possible place to start.

That is very helpful.

"Hooray, I've been quoted for the first time." Anyways.
I'm still looking forward to seeing how all of this goes. So in the interest of seeing a quality campaign, I heartily recommend 5e.
It's more flexible to what you want than you might expect.
For example,
In one case in 5e, I was fighting a dragon-ish guard dog, and losing.
What surprised me is that sentient carnivorous stalactite dropped down, Tapped me on the shoulder, and asked if I wanted help.
He was mostly trying to turn the dog into his dinner. I cartwheeled out of the room. (Don't ask.)

My point is that 5e Can probably run this campaign without a hitch, If it ran that incident.
So I hope it can work out for you.

The problem is there is no official kobold or monster material, and I'm generally weary of homebrew. 5e thus far rejects both monstrous and Evil characters pretty hard. But the ease of character creation lends itself to a high mortality campaign.

PF/3.5 has an abundance of kobold related materials.

One thing you should consider before the game starts is how simulation-y you want to go. Are you going to make the players design food production areas, storerooms, temples, workshops, and living quarters in addition to the dungeon? If you do, I'd recommend going with an extremely simplified "1 5' square of food production supports 2 kobolds" or something similarly abstract. If not, you can just label an area "the warrens" and leave it at that.

Probably not very much. I am kind of assuming that if the initially small tribe is resourceful enough to keep attackers at bay, then the noncombatants are probably resourceful enough to feed every one. The resources they will have to manage would be those required to defend the village: their fellow soldiers, the workers to dig tunnels, the masons to build the fortifications, the specialists to built traps, the smiths to make weapons and retool loot, the stables to house dire weasels, the trade to obtain material components and special trap parts, etc.

In other words, in order to defend their land with more than just hide armor and spears, they need to be able to obtain those things, which is not an easy task for cavedwelling kobolds in the middle of butt-**** nowhere.

You've mentioned this dungeon is going to be "tower defense like". In those, there's usually an area where the enemy is trying to reach, and if they reach it bad things happen to the defenders. You've said that this "goal area" is the entrance to the real Wizard-who-did-it's tomb, so why don't the kobolds just let the adventurers through? Is that tomb a (un)holy site for the kobolds? Is there a prophecy that states "if anyone disturbs my tomb my wrath shall be swift and terrible, especially on anything short and scaly"?

Because the adventurers are racists who would rather kill kobolds than bother speaking with them. This is a cynical, satirical campaign. In part, it should to a degree satire the behavior of unscrupulous PCs the world over, by portraying that conflict from the view of the dungeon-dwelling monsters, who live in constant fear that wayward adventurers will show up and murder them all and steal their stuff.

The kobold-adventurer conflict is intended to be somewhat irrational. The average adventurer is just too full of themself to assume a group of dungeon-dwelling kobolds are anything more evil little creatures out to kill them. The kobolds on the other hand could care less about the actual tomb (which they view as a cursed place no one returns from), they just don't want dangerous murderhobos waltzing through their village to get there. Plus, dead adventurers drop nice loot.

Are there any other monsters living in the caverns with the kobolds? How do they fit into the equation? Not everything needs to be tamed or domesticated by the players. Rather than building a chute that drops adventurers into a time-expensive and costly vat of acid, why not use that chute to drop them into a wild troll den?

Related, how are the PCs going to recruit new kobolds? Will there be a substantial time lapse between adventurer attacks, or will they have to recruit new kobolds?

Finally, having an amoral merchant type who comes through and trades hard-to-get items for the kobolds' ill-gotten spoils is always lots of fun.

I intend to inhabit the lands that surround them with a few additional monster groups, mostly ones that could feasibly be PCs (goblins or other potential level-adjustmentless races). If the players ally with them, they can optionally respawn as one.

There will probably be a few big, unruly mobs that the players can fight, tame, or live in tenuous peace with.

As for recruiting more, I'm thinking most kobold resources will be provided by the tribe as it grows (kobolds bred like rabbits and mature quickly). Obviously, if they develop a reputation for giving the adventurers the boot, maybe I'll think of a means that they could recruit kobolds from other tribes to join them.

As for unscrupulous merchants? I very much plan for them to be obtainable resources.

I'm not sure a system exists for this that I would recommend.

The closest I have is Dungeon Lords, which is a board game that is not an RPG. You may be best off building something from the ground up, to be honest. (Though this will obviously take a long time)

The temptation to build a custom system for this is very strong. I just don't know if I'd even have the time and I would certainly want interested co-conspirators and testers before I was willing to put in the effort.

Have a good day!

I feel like you are only required to wish people a good day at minimum once per thread, at most once per actual day.