So I posted some possible house rules a couple days ago that could be used to distinguish different weapons from each other withOUT resorting to "variable weapon damage" (which I'm not a huge fan of, for a number of reasons). And I'm sure my own players are rather worried about what this will mean for them when they encounter yet another horde of spear-wielding goblins...will they automatically lose initiative and fall pierced with many sharp-stabbies (the spear-equivalent of what I like to call a "Charlie Manson Special")?
Remember my post about sentient (i.e. "weapon/tool-using") monsters? Okay, well, in my book they might use weapons, but they're certainly not the sharpest of knives, if you catch my drift. Except for the very special (or very rare) unique individual, humanoids don't have the brains to execute special maneuvers...they're just trying to put the PCs down for a dirt-nap. Even though the orc horde is armed with battle axes, they still roll the standard damage for their monster type, which to me represents simply how effective they are in combat.
Is this "fair?" Who cares! They're monsters! And unlike some editions of D&D, monsters work differently from player characters...they all roll D8 for hit points. They have saves that may be higher or lower than their own Hit Dice. They can do more damage unarmed that a PC (who is limited to 1-2 points); some have multiple attacks (like minotaurs and troglodytes). They do not possess ability scores.
Does this mean an orc is hitting a person with the wrong edge of the axe? No. It just means, that PCs are a step ahead of these poor saps with their crooked blades and sawed-off spears, and rusty cleaver-like knives. Besides, it's much easier for ME (as the DM) to NOT have to track this kind of thing!
Though, of course there is a player-saving reason here as well...giving monsters ANY kind of "critical hit" ability is an "advantage monster" kind of thang, seeing as how their numbers are (abstractly) unlimited compared to the finite adventurers. And while the "doesn't work on characters of higher level" rule might save PCs from kobolds or humanoids of lesser value, 1st level characters are still apt to encounter orcs, 2nd level characters will probably see a few gnolls, and it goes without saying that the occasional ogre is a staple of most dungeon adventures.
Nope...only the rare "badass" monster will be able to use these weapons "traits" against PCs...and generally PCs get a sense of when they're up against this kind of opponent (he gets a different description from the DM than your average, run-o-the-mill Shmoe). 'Course, it's just as easy to say "these hobgoblins are so huge they get +2 to damage rolls and fight like 4HD monsters;" that kind of thing is found all the time in D&D adventure modules: creatures that "break the mold," so to speak. Monsters are just stat-lines/profiles in B/X...you can make 'em do whatever you want.
Now what about human monsters, i.e. NPCs? Well, unless they are an actual adventuring class, then no, they don't get any special benefits from certain weapons, either. Only heroic adventurers (like the PCs and "classed" NPCs) gain any special benefit from using particular weapons. But, again, they're still subject to level restriction so, for example, an evil dwarf of 3rd level would be unable to K.O. a PC fighter of 4th level with his trusty war hammer.
Okay, that's enough to chew on for now.