GRENDEL MENDEL II: An Applied Example of Punnett Squares For Monster Design

Good enemy design, enviornmental complications,
& NPC goals make for good fights

Here is a practical application of my Punnett Squares For Monster Design idea.

In a few posts I have alluded to trying to design a dungeon called The Black Keep. The first level of that dungeon is a classic ruined moat-house-turned-bandit-camp. So there is a lot of opportunity for bandits to appear and and a lot of opportunities make them a bit better than the standard stat block below:

Bandit: AC 13, HD 1, 1 x weapon (1d6), MV 40, ML 8

Looking back at the Punnet Square post we have four categories again: melee x damage, melee x special, ranged x damage, ranged x special

Right off the bat I don't want to have to think about making groups bandits. I want to be able to roll 3-6 d8's for hit-points and go from there. How about hit points rolled determine the catagory on the Punnet Square?

Given that ranged enemies require extra effort for PCs to get to them and melee enemies need some extra HP to get to survive first contact, we can arrange things like so that "ranged" is the lower 50% of hit die and "melee" is the upper 50%. I like putting the "specials" on the end of the hit die, upper and lower 25%, allowing for a strong flavor in those catagories with them appearing too frequently.

Developing "mobs" and the "leader"

The Rot Hounds are people overtaxed, pushed off lands, and/or former rank-and-file military who have been screwed by nobility. They also have a supply of carnivorous frogs. So this can inform the square.

Rot Hounds Punnet Square 
Behavior: Can be bribed; capture magic-users for Henry

1-2 hp Ranged x Special: AC 10 Spear +Frogling 1x attack 
3-4 hp Ranged x Damage: AC 12 Short Bow & Dagger; will stay at range then run if able
5-6 hp Melee x Damage: AC 12 Sickles & Spears
7-8 hp Melee x Special: AC 14 Two-handed axe, +1 HD

The leader of this group is Henry Hounds-Head, a cursed former pikeman who blames the nobility for his ruin. Now robs the rich to build an army and seeks to undo the curse.

Like the Hounds, I tried to conceptualize around a known D&D monsters. For Henry Hounds-Head, I chose the beserker.

Beserker: AC 12, HD 1+1*, 1 x weapon (1d8), MV 40, ML 12;
Rage: +2 to-hit against humanoids

I was particularly drawn to the to-hit bonus as a way to express Henry's rage again the nobility. But we can make this leader a little more dynamic in both personality and behavior on the field. When creating a singular monster, I like to each cross as a reminder to include melee, range, and specials in a singular creatures. This is because they have to face off against generally a party of 4-6 PCs with some combination of melee, range, and magic and an HD total of 4-6!

Henry Hounds-Head
Behavior: Wants to recruit & will capture magic-users; hates nobility & connected to The Order

AC 14, HD 4, 1x as weapon, MV 40, ML 10

Melee x Damage: Two-handed Axe (1d8), not "slow"
Melee x Special:  On a "1" damage, weapon is stripped from PCs hands
Ranged x Damage: Spear (1d6)
Ranged x Special: On a miss of 11+, PC saves vs Paralysis or be knocked prone

RAGE: +2 to-hit against humanoids
KEEN SENSES: Animal-headed & suprised only on a 1-in-6
SOUND of BATTLE: 4 Bandits in the area after 1 round of battle

I chose 4 HD because by OD&D standards this confers "hero" status. I guess I could add some +X hp in order to keep him out of range of Sleep, but I am writing a 1st level adventure so maybe don't want to go too hard.

Related to the "hero" staus, I could either give Henry an additional attack per round or could even go so far has allowing a division of attacks equal to HD among non-hero targets. But I dunno, if I got that route he might be too tough.