[D&D] Designing Humanoid Encounters
So. You're DMing a D&D session, and your PCs are getting ready to go deal with some Kobold bandits. They've heard rumors that these Kobolds are harassing pilgrims and merchants and demanding tolls for traveling on the King's Road. The PCs have just arrived in town, and with some careful information-gathering, and a Knowledge check or two, have figured that the Kobolds probably live in the abandoned mines a couple days' walk outside the town, in the hills nearby. The town itself has about 400 inhabitants, and has a regular militia and guard of just over 20, plus a few auxiliaries who have been trying to guard the roads to and from the area. They never seem the catch the Kobolds, though.
So, you want to make this an exciting encounter, level-appropriate and challenging. I personally DM in 3.5e, but some of this could also apply to 4e-- a lot of it is conceptual. I'm going to be talking about how we make this band of Kobolds a good challenge. Goblins work too, but Kobolds are better for reasons I'll go into shortly. So, let's talk about what a Kobold has that a human doesn't, in terms of strengths and weaknesses. Since this is 3.5e, I'll be using SRD sources for my information, but some of this should carry over.
-4 Strength, +2 Dexterity, -2 Constitution.
Small size: +1 Armor Class, +1 attack, +4 Hide
A kobold’s base land speed is 30 feet.
Darkvision out to 60 feet.
+2 Craft (traps), +2 Profession (miner), +2 Search
+1 natural armor bonus.
Special Qualities (see above): Light sensitivity (-1 on attack rolls in daylight)
Automatic Languages: Draconic. Bonus Languages: Common, Undercommon.
Immediately, we get an idea of what kind of creature this is. Kobolds are weak, and they are unhealthy, but they are nimble, small, and quick. They can see with no light, they are natural diggers and trappers, and do poorly in the daylight. These creatures are often used by DMs since, with their -4 strength and -2 constitution, they can't take the PCs in a straight fight. Indeed, if it comes to melee combat, the average hero will cut through Kobolds like butter. It's basically a slaughter in melee, since a creature wielding a small spear with 6 strength will be doing an astonishing 1d6-2 damage. And if he's using a short sword or half-spear? 1d4-2 damage. Ew.
What lies just below the surface, though, is something surprising about Kobolds. Their Alignment is Usually Lawful Evil, and they have no mental stat penalties. Both of these facts are non-trivial, and are also what make Kobolds more interesting than Goblins, which are Chaotic and have mental stat penalties. First off, Kobolds are Lawful creatures, which means they are prone to planning and forming strong organizations and tight bonds. They naturally develop hierarchies and chains of command, and follow them. Secondly, they are as intelligent as humans and elves, and actually mentally superior to Dwarves, Half-Orcs, and basically any of the powerful enemies PCs tend to fight. Together, these traits means that our Kobold bandits are intelligent and organized, and assuming they're aware of their strengths and weaknesses (and they are), they'll do everything they can to mitigate them.
Think for a moment, of this situation: the PCs have to rally the town guard to fight off a small number of Ogres that are coming to ravage the town. There is time to prepare, but they know the Ogres WILL come. They build barricades, put down traps to slow the giants down, and create chokepoints and areas where they can attack with crossbows and ranged weapons. Because the average human has no chance against an Ogre, the PCs split up and command the town guard in small strike forces, attacking at long distance with Crossbows before fading into the trees, backing up across bridges, or escaping into the hills or up walls. They harry and press the enemy, never letting the Ogres bring their superior power to bear on the small humans. They'll focus on their strengths as smaller, more mobile creatures with time to prepare.
This is exactly what Kobolds will do. Now, your average Kobold is not going to be dumber than a typical town guardsman. In fact, if it makes its living via banditry and was never caught, requiring adventurers to be hired to come kill it, it's probably smarter. The Kobold leader is probably a skilled tactician and knew this day would come. He also is aware of his own physical limitations and that of his allies, and that the opponents they face are likely better-armed and more magically skilled than they are. What would you do as the Kobold leader? Well, you'd fill the forest with scouts, keeping an eye out for potential adventurers. You might spy on the town if you can get close enough or can bribe a town guard to look the other way, and know for sure where and when the PCs are coming.
And when the PCs arrive, you'll be gone. And if you can't be gone, you'll be ready. Barricades with crossbow-slits, secret passages in the walls, ceiling and floor of every room (Kobold-sized, of course, not human-sized)-- a drafty room that blows out torches, which are immaterial to Kobolds who can see in the dark. The Adventurers will never catch you cornered or get your men (kobolds, whatever) into melee if you can help it. Your number 1 goal is to mitigate losses and force them to retreat. You'll do it without them ever seeing you if you can. And, as a Kobold, you'll have the smarts to do it. And if things seem to turn bad? Well, your wealth is safely stashed somewhere else, and you and all your men will run via escape route while the last set of smoke bombs go off and you set fire to the barricades and wooden supports in vital areas, causing an imminent cave-in in the cavern complex.
You might not be strong, or tough, but you're mean, and just as smart as any human leader would be. Smarter, even, if you're going to survive in a harsh world as Kobold bandit. You'll be damned if you let some big, slow-moving, near-sighted humans beat you in the dark and on your home turf. And if they do, you're not going to let any of your men die if you can help it.