Blade-Eater Plate, A System-Agnostic Magic Item

Blade-Eater Plate

Description:  A full suit of plate armor made of lusterless gray metal, well-crafted but utilitarian in appearance.  The metal feels strangely rough to the touch, like brushing against a file.  Magical senses reveal a modest aura of enhancement magic, while more intensive examination reveals a complex transformative dweomer overlaid atop it.     

Powers:  Blade-Eater Plate performs as magically enhanced armor suitable to your campaign (leaning toward the lower power levels, a +1 or +2 in D&D) with an added benefit.  Weapons that rely of slashing, cutting, or piercing to do damage that roll a natural odd result (hit or miss) on their attack die (a d20 in D&D) will suffer a -1 penalty to future attack rolls in that battle as the armor's rough surface blunts the edge or point of the weapon.  This penalty stacks to a maximum of -4, but if the effect triggers five or more times the weapon's damage is also halved (round up) till the end of the fight.  This obviously won't have much effect on ranged attacks, although projectiles that trigger the armor will require sharpening (see below) if recovered for re-use later. 

Blunt weapons are unaffected.

Natural attacks other than simple bludgeoning strikes are affected as teeth, horns, or claws are dulled.  Ones that rely on constriction or restraint to function will be similarly penalized as grasping the armor in combat is akin to taking a firm hold on a power sander.  Lassos, bolas, and similar constricting weapons will simply break on an odd attack roll if made of anything less sturdy than chain links. 

Magical weapons will recover from these penalties on their own within 1d6 minutes after the battle ends.  Mundane gear will require considerable repair time using a whetstone and (if the penalty reached -3 or worse) smith's tools.

Possible Origins:  Sages credit the first suits of Blade-Eater Plate to several sources, including Dwarven artisans (who imbued the suits with the essential nature of rough mountain granite), a forgotten order of warrior priests (whose vows forbid the spilling their enemies' blood with the sword  and sought to punish foes who tried to spill their own), and an exceptionally incompetent wizard (who botched the creation of a suit of shining royal armor in a unintentionally beneficial way).  

Complications:  This armor is supernaturally abrasive to the touch.  Any clothing worn over the armor will be shredded to rags within hours, so no cloaks, tabards or heraldic surcoats for the wearer.  Care must be taken to avoid damaging the garb and gear of others when maneuvering in close quarters.  Ropes are likely to suffer damage from the armor, so climbing them can be fraught with peril.  The wearer can also expect to regularly (albeit unintentionally) snag and damage tapestries, curtains and the like.  Don't even think about wearing this armor while sleeping unless you hate your bedroll - and possibly your tent.  If you spend much time riding expect to spend a lot of time and money repairing and replacing your tack, although the tougher leather will resist damage much longer than fabrics do.

On the plus side, if you actually need to dull a blade or blunt an arrowhead, you can do so by simply dragging it across the armor's plates.  There's some potential for sabotaging an armory or a hunting rival's arrows there. 

Design Commentary:  The secondary blunting effect on this armor is quite strong in combat (hence the recommendation for keeping its enhancement bonus low) but can and should be a torment in everyday life.  Some owners might even consider this a cursed item, and an adventurer might well be gifted a suit of the armor by a noble patron who's grown tired of watching it collect dust as an unusable family heirloom.

If your game system uses armor that stops damage (rather than making you harder to land a blow on as D&D does) you'll need to hack this a bit.  Best approach is probably to just apply a stacking -1 to damage rolls on odd die hit rolls (capping at -4) but it will vary depending on the system involved.  A penalty of -4 to damage is quite a lot in TFT or Runequest, for example, but so is -4 to hit in D&D.