Axe of the Wood-friend, A System-Agnostic Magic Item

Axe of the Wood-friend

Description:  A sturdy but surprisingly light woodsman's axe, suitable for one or two-handed use.  The haft seems to be made of living wood complete with oak-like bark but somehow still provides a sure grip.  The axe-head bears elven runes that roughly translate to "Friend of the Wood" and which, in the absence of other light, radiate a pale silver light about equivalent to a torch.  Even the most basic of magical senses will detect a very strong aura of enhancement magic. 

Powers:  The Axe of the Wood-friend is a powerfully enchanted blade (+5 to attack and damage in D&D equivalencies, or on par with the most potent bonuses your campaign allows) that can cleave metal, stone, and living flesh with unnatural ease.  However, it deals only half damage (without magical bonuses) against foes dressed in leather or hide armor.  The weapon always does minimum damage (again without magical bonuses) to elves, living plants, and any kind of plant creature (eg dryads, ents).  Dead (or undead) plant matter takes damage normally, including the magical damage bonus, as do creatures with only natural armor from their hide, shell, or scales.  

Possible Origins:  These axes are creations of the elves, gifted only to those they trust - but perhaps not completely.  The first examples were given to Dwarven allies in days of yore, but many champions of other races who've done service to elven rulers and communities have been similarly rewarded.  To date no others have recreated the enchantment, and there's some doubt that a non-elf would wish to do so.

Complications:  Whenever a creature is slain by one of these potent axes, the site of its death becomes unnaturally fertile forever after to all forms of plant life.  The exact area affected varies with the size and power of the victim, ranging from about a 30' radius for a simple human man at arms up to several square miles for something like an adult dragon.  

Vegetation appropriate to the terrain and climate will appear in the area within a few days, growing with unnatural speed and becoming thicker over time.  Even unsuitable locales like caverns or bare stone will be overgrown with moss and lichen in short order.  Deserts will sprout cacti and wiry scrub, farmland will struggle with weeds and saplings even as their crop yields boom, and open plains will rapidly transform into lush groves of trees.  Actual wooded areas become denser, grander, and increasingly "elven" in nature, with exotic plants and sylvan creatures appearing seemingly from nowhere.

All this rampant growth can be controlled or even eradicated through vigorous effort, but outbreaks of swiftly-growing vegetation will recur regularly until suitable ritual countermagics are performed - something that may be violently opposed by any new inhabitants of the area who were drawn by the magics involved.

For reasons that remain unclear, none of these effects occur if the killing was performed by an elf or half-elf wielding the axe, nor do such wielders enjoy any benefits when using it as a weapon.  The drawbacks (half damage against certain targets) remain in effect.

Design Commentary:  These things are trapped rewards of a peculiarly elven sort.  They can hand these axes out to friends without fear of the weapons being turned against them, and every victory won with an Axe of the Wood-friend helps adds a little more potential territory to the elven domains.  Also, scrubbing moss off their stonework keeps the Dwarves busy doing things besides cutting down trees and annoying elvenkind.