The Lesser Evil
by Kit NavarroInspiring idea: The human mouth is absolutely teeming with bacteria, most of them potentially lethal if found elsewhere in the body (such as in the respiratory tract or the blood stream). But scientists believe that one purpose such bacterial population are massive and overwhelming is to prevent other species of even more dangerous micro-organisms from growing into significant numbers.
Translation to adventure scenario (Adventure Template): In the setting (whatever village or town), there has always been a constant threat (The Lesser Evil) plaguing the area. Recently, certain mighty and authoritative forces (probably of the self-righteous Lawful Good type) have decided to effectively eradicate this Lesser Evil (The PCs can even be a part of this prologue adventure). They succeed and it seems everyone would live happily ever after. Little do they know, that the Lesser Evil had always been there (perhaps placed by some Immortal) to prevent a Greater Evil from rising. So soon after the newfound peace (the calm before the storm), the vacuum left by the Lesser Evil is being filled by a more dangerous, more deadly, more insidious threat... And this is where the PCs come in...
Scenario Variations (Fill in the blanks):
The Lesser Evil is a tribe of humanoids living in the caves of nearby gorges. Their presence is the caves have long deterred the Shadow Elves (from Aengmor or even Schattenalfheim) from coming to the surface--until the local ruler decided to send the army or several parties of adventurers eradicate them. Now, the local citizens are threatened by nightly attacks of these dark-skinned elves.
The Lesser Evil is a coven of medusae lurking in the ruins of the old palace and fortress along the old trade route. The merchant houses have decided to pour enough money onto the problem, sending mercenaries to eliminate the medusae. Unfortunately, their extinction has emboldened a rival coven of lamara, hags, or crones of chaos, to use their shapeshifting magic to infiltrate the caravans along the newly reopened trade route, bringing the threat into the more civilised population.
The Lesser Evil is a cult of Nyx*, reported to perform their rituals in the dark of night, celebrating destruction and chaos as a natural part of nature. The Lawful Good church of Ixion have sent their paladins to eliminate these worshippers. But now, a cult of murderous worshippers of Hel or Thanatos have come a-murdering, and the good folk have begun to lose faith that their church can truly protect them.
*Note: Though Nyx is a powerful Immortal, she has no single base of worshippers, but probably numerous cults throughout all cultures.
*Second Note: Nyx would be a perfect Immortal who would advocate such a balance of evil with a lesser evil. The humanoids or medusae could be worshippers of Nyx, placed there by the Immortal to preserve the Entropic ecology.
The Lesser Evil is a horde of disturbing and noxious, but otherwise tolerable undead. They are under the control of an exiled Glantrian wizard (a practitioner of the unstigmatised, perfectly acceptable Glantrian art of "Necromancie Applique" or "Practical Necromancy") or a necromantic cleric of Nyx, who is continuously replenishing his army of undead, to deter an increasingly organised humanoid tribe in the nearby wildlands. When the mage guild or local temple moves to purge this evil magic from the land, the humanoid threat becomes a reality.
(Note: We've come full circle here with the humanoids!)
One highly magical scenario:
The Lesser Evil is an enchanter, a dimensionalist, a Krondaharan Dream Master, or simply a wizard who has been studying the Nightmare Dimension. His tapping into such magic has caused a long history of nightmares, sleepwalkers, insomniacs, addled minds, and outright madness among the local folk. When his arcana practices are discovered, his magical research is stopped. It will be later discovered that what drew the wizard to the area was the opening of a portal from the Nightmare Dimension, and that his practice of magic actually prevented the entrance of brain-eaters and mindflayers... but no more.
An Immortal Level adventure:
The Lesser Evil is a powerful rogue demon or a group of demons acting independently from the Sphere of Entropy, who are infest a specific area on the Material Plane or even a small pocket plane. Immortal history reveals that the area or plane hides a mystical nexus, which certain Immortal powers believed must be liberated of these chaotic evil beings. The quest is undertaken, the demons are slain and the nexus opens, and through it enters devils, lawful evil fiends never before seen in the Mystaraverse! It is then theorised that the reason that some long forgotten Entropic Immortal (or even perhaps an Old One) assigned these demons there are to prevent the entrance of devils into this dimension.