Got a Real World Weapons or Armour Question? Mk XIII

[Brother Oni]

Maybe we should start paying Thiel royalties...

This thread is a resource for getting information about real life weapons and armor. Normally this thread would be in Friendly Banter, but the concept has always been that the information is for RPG players and DMs so they can use it to make their games better.

A few rules for this thread:

This thread is for asking questions about how weapons and armor really work. As such, it's not going to include game rule statistics. If you have such a question, especially if it stems from an answer or question in this thread, feel free to start a new thread and include a link back to here. If you do ask a rule question here, you'll be asked to move it elsewhere, and then we'll be happy to help out with it.

Any weapon or time period is open for questions. Medieval and ancient warfare questions seem to predominate, but since there are many games set in other periods as well, feel free to ask about any weapon. This includes futuristic ones - but be aware that these will be likely assessed according to their real life feasibility. Thus, phasers, for example, will be talked about in real-world science and physics terms rather than the Star Trek canon. If you want to discuss a fictional weapon from a particular source according to the canonical explanation, please start a new thread for it.

Please try to cite your claims if possible. If you know of a citation for a particular piece of information, please include it. However, everyone should be aware that sometimes even the experts don't agree, so it's quite possible to have two conflicting answers to the same question. This isn't a problem; the asker of the question can examine the information and decide which side to go with. The purpose of the thread is to provide as much information as possible. Debates are fine, but be sure to keep it a friendly debate (even if the experts can't!).

No modern real-world political discussion. As the great Carl von Clausevitz once said, "War is merely the continuation of policy by other means," so poltics and war are heavily intertwined. However, politics are a big hot-button issue and one banned on these boards, so avoid political analysis if at all possible (this thread is primarily about military hardware). There's more leeway on this for anything prior to about 1800, but be very careful with all of it, and anything past 1900 is surely not open for analysis. (I know these are arbitrary dates, but any dates would be, and I feel these ones are reasonable.)

No graphic descriptions. War is violent, dirty, and horrific, and anyone discussing it should be keenly aware of that. However, on this board graphic descriptions of violence (or sexuality) are not allowed, so please avoid them.

Previous Threads:
Thread V
Thread VI
Thread VII
Thread VIII
Thread IX
Thread X
Thread XI
Thread XII

[snowblizz]

First post! Not funny? Not even a little? Ah well..

Regarding some of the topics of the end of last thread, gunpowder weapons and naval combat and pirates. Even the discussion of sources ties into this.

Love the Mythbusters. But have been bothered by their "proving" that splinters from cannon balls weren't the danger they are often perceived to be. In particular when they place a bunch of pigs in a tight file and shoot through them and it's all "see it went through all of them". So a couple of issues.
1. that's not really how packed a ship would be surely? well excepting a slave ship and then it's "cargo" really... a ship is tightly spaced yes but people wouldn't be lining up like that.
2. they finally used a real cannon, IIRC a 6 pounder, but that's pretty weak for a traditional naval gun innit? That's light field artillery. 24 pounds and up would surely be more in the range of a serious break the planks kind of naval gun? Would that be doing more damage and increasing splintering, but with no perceivable increase in direct "killingness" of a larger cannon ball. Anyone hit would be just as dead after all, more messed up, but that don't count if you die.
3. The traditional view of the matter with splinters, where then does that come from. Are there no sources, I'd think there was casualty reports, ship's surgeons statements, reports, memoirs? Did they just ignore that, or is there little to go on.

[Boci]

Aesthetics of parry-less sword combat:

Okay, so my understanding of the sword combat is that parrying was not a common move outside fencing, but I am then having trouble imagining how it would in fact work, what would a realistic sword fight look in your typical fantasy setting, assuming magic wasn't playing any major roles?

I understand (or guess) that part of the problem is the popular fantasy model of a guy in light or no armour, wielding a sword in either both hands, or in one hand with his offhand empty. Either way, no shield. This does not having many real life counterparts. But if we stick to this fantasy archetype, how would a fight between between two such individuals work? My understanding if parrying wasn't used because it damaged the sword, but if someone swings at my head then a damaged sword could be considered a fair risk if it reduces the chance of me suffering a mortal wound. Can you help me out?

[warty goblin]

Aesthetics of parry-less sword combat:

Okay, so my understanding of the sword combat is that parrying was not a common move outside fencing, but I am then having trouble imagining how it would in fact work, what would a realistic sword fight look in your typical fantasy setting, assuming magic wasn't playing any major roles?

I understand (or guess) that part of the problem is the popular fantasy model of a guy in light or no armour, wielding a sword in either both hands, or in one hand with his offhand empty. Either way, no shield. This does not having many real life counterparts. But if we stick to this fantasy archetype, how would a fight between between two such individuals work? My understanding if parrying wasn't used because it damaged the sword, but if someone swings at my head then a damaged sword could be considered a fair risk if it reduces the chance of me suffering a mortal wound. Can you help me out?

How does a fight between two lunkheads in loincloths with akimbo swords end? Dead lunkheads.

Whether or not a parrying was used I think depends mostly on how you define parrying. Simply slamming the edge of your blade into your enemy's blade probably wasn't such a common technique, since it's both hard on the equipment and also crappy swordsmanship. Using your blade to set aside another's strike however is good technique, since it protects you, gives you control of your enemy's weapon if you do it right, and therefore allows for your own attacks.



Otherwise

[Rhynn]

Okay, so my understanding of the sword combat is that parrying was not a common move outside fencing, but I am then having trouble imagining how it would in fact work, what would a realistic sword fight look in your typical fantasy setting, assuming magic wasn't playing any major roles?

Where did you get this impression? Sword contact was absolutely a part of rapier fencing (granted, it wasn't double-action parrying, but simultaneously deflecting an attack and making your own) and longsword combat (where parries regularly lead to winding & binding or counters), the two best-documented Renaissance European forms of sword-fighting. In any sword combat, your order of business is going to be:
1. Negate an opponent's attack (either pre-emptively - voiding or controlling the sword - or by parrying)
2. Strike back

I can't really speak to kenjutsu, etc.; I did kendo years ago, but that's a sport very, very far removed from actual combat skills. AFAIK there are parry-counters even in kendo, though - you'd have to be crazy not to use a weapon you've got to defend yourself, really. (Blocking, which is distinct from parrying - more "passive" if you will - is generally frowned upon, though.)

My understanding if parrying wasn't used because it damaged the sword, but if someone swings at my head then a damaged sword could be considered a fair risk if it reduces the chance of me suffering a mortal wound. Can you help me out?

That's pretty much complete nonsense. If you know what you're doing, parrying isn't going to damage your sword appreciably - not enough to be a concern in a fight, anyway.

What sword-fights will look like is going to vary by weapon. Here's an awesme video of unarmored longsword combat (in costume) showing strikes, parries, counters, counter-counters, counter-counter-counters, and so on...

There's a lot of other videos available on YouTube, including stuff like Swordfish tournaments, etc. (Although anything with free play is going to look a bit "sporty" because nobody is actually in danger of injury or death.) Just start following related videos from the above one.

Edit:
JustSomeGuy asked about sailing with the wind...

A sailing ship had multiple sails on masts along its length. If the wind is coming from directly behind the ship, it only catches the first sail it hits (especially if they're square-rigged). If the wind is at an angle from behind the ship (say between 15 and 75 degrees, whatever), it's going to hit multiple sails - preferrably all of them. More sails getting the wind means more square footage getting pushed means faster travel.

[Boci]

Where did you get this impression? Sword contact was absolutely a part of rapier fencing

I know that, I'm just not interested in rapier fencing for the purpose of this question. Just to clarify I am referring to European blades, just not the rapier.

That's pretty much complete nonsense. If you know what you're doing, parrying isn't going to damage your sword appreciably - not enough to be a concern in a fight, anyway.

Is there any film scene with shows parrying by people who know what they are doing?

What sword-fights will look like is going to vary by weapon. Here's an awesme video of unarmored longsword combat (in costume) showing strikes, parries, counters, counter-counters, counter-counter-counters, and so on...

Okay, and is that the normal speed and force you would normally strike with? Because some of those moves (the upward blocking ones) look like it will result banging swords together.

[warty goblin]

Okay, and is that the normal speed and force you would normally strike with? Because some of those moves (the upward blocking ones) look like it will result banging swords together.

No. But where the blades make contact also matters; the section nearest the guard of a longsword is, I believe, generally not actually sharp and hence quite resistant to being damaged from hitting another blade.

[Boci]

No. But where the blades make contact also matters; the section nearest the guard of a longsword is, I believe, generally not actually sharp and hence quite resistant to being damaged from hitting another blade.

Okay, is that also where they grab each other blades? Because that did seem like a dumb idea, but if its blunt then I can see how it work.

[warty goblin]

Okay, is that also where they grab each other blades? Because that did seem like a dumb idea, but if its blunt then I can see how it work.

It takes an extremely sharp blade to cut flesh - particularly the calloused palm of somebody who uses their hands - through just static pressure*. It takes pressure and draw, the blade has to be pulled across the flesh. Just like cutting bread or steak, you don't just lean on knife and push it through, you pull the blade across, and it bites. Proper technique for grabbing an enemy's blade is about keeping them from being able to pull the thing out of your hands and lacerate your palms through multiple points of contact and/or flexing the blade.

Grabbing the enemy's sword is also not a tactic one executes for very long; just long enough to hopefully hit them a good one with your weapon.

*You can sharpen steel enough to do this. Swords are generally not this sharp, since there's little point to grinding away more of your blade for a small increase in cutting ability. I've tried pressing most of the knives in my collection into my palms with considerable force, and none of them do more than leave a small red mark that disappears after a few minutes. And I keep my knives plenty sharp for their purposes. But I wouldn't try it with a scalpel.

[Boci]

*You can sharpen steel enough to do this. Swords are generally not this sharp, since there's little point to grinding away more of your blade for a small increase in cutting ability. I've tried pressing most of the knives in my collection into my palms with considerable force, and none of them do more than leave a small red mark that disappears after a few minutes. And I keep my knives plenty sharp for their purposes. But I wouldn't try it with a scalpel.

So aside from the katana (which I'm guessing would be sharp enough to do so. I may be wrong) was there any sword that was typically sharpened enough to make grabbing it by the blade, even in a controlled way for a short time, dangerous?

[warty goblin]

So aside from the katana (which I'm guessing would be sharp enough to do so. I may be wrong) was there any sword that was typically sharpened enough to make grabbing it by the blade, even in a controlled way for a short time, dangerous?

I don't think the katana was that much sharper than any other sort of sword, really. How sharp you can get a blade is to some degree a function of the steel, but given decent steel the better question is how sharp you want it. Every time you sharpen a blade, you grind it down; I've got a kitchen knife of unknown age that's lost a good quarter of an inch from sharpening. And the sharper you keep it, the more sharpening it will require after every use, as you grind the bevels backwards into the body of the blade. So you've got to weigh the advantages of a sharper blade against the disadvantages of maintaining it with such an edge. For a sword, the advantages of being scalpel sharp are pretty minimal. They're already sharp enough to chop up meat plenty good when used with conviction.

And of course grabbing a sword by the blade is dangerous; you're grabbing a three foot long meat cleaver in the hands of a person who is trying to chop you up for dogmeat. The entire enterprise is fundamentally dangerous, the only question is whether grabbing the blade is worth the risk.

[Rhynn]

Didn't somebody just link a YouTube demonstration video where they cut tatami or something with a longsword, then grab the blade from a swing with a bare hand, or something?

If you don't know what's being done and how, anything can look like magic - including swordsmanship. The grabs and sword-binding is pretty "standard" stuff from the manuals (although obviously it's even more standard in harnischfechten, but the video obviously shows unarmored techniques).

The video doesn't look quite "top-speed" to me, but like I said, watch more on YouTube. Swordfish longsword for instance probably has a more "realistic" speed than a video that's meant to demonstrate moves. It's also less "clean," although like I said, it's going to look "sporty." You're never going to actually see real medieval/renaissance swordfights - nobody fights with real longswords to kill someone anymore. You can get a good approximate idea from watching free play/sport (like Swordfish) and technique demos, though.

[Boci]

So to round up: parrying does work with long sword, just imagine:
Angled deflections rather than blade to blade interceptions
Use of the crossguard
Use of the base of the blade where it is strongest
And grabbing an opponents weapon, whilst dangerous, is not as stupid as it initially seems.

Is that about right?

What about other types of sword? Say two handed sword, cutlasses or samurai combat?

[Mike_G]

Using the part of the blade near the hilt also give you an advantage in leverage over and above it being the thickest, sturdiest part of the blade. The part near the hilt was called the "strong" or "forte" where the part near the point was called the "weak" or "foible." If I put the strong of my blade against the weak of yours, I can move your blade where I want it very easily.

You can try this with rulers or dowels or even sticks. Have your buddy hold his out, and see how easy it is to control if you put your strong against he weak. Conversely, it's very hard to move his blade with your weak against his strong. So parrying, beating, binding etc with the strong of your blade against the weak of the enemy's works pretty well.

Add a crossguard or more complex quillons and it becomes very easy to trap his blade, keep it out of the way while you put your point in his body.

For most swords used alone, I would think this would be a big part of the technique. Maybe not so much for swords intended to be used with a shield. I'll be honest, I don't know much sword and shield technique.

[warty goblin]

For most swords used alone, I would think this would be a big part of the technique. Maybe not so much for swords intended to be used with a shield. I'll be honest, I don't know much sword and shield technique.

My limited experience of the form is that it's a lot of smashing boards together, and then somebody gets stabbed in the ankle.

[oudeis]

This is a very informative video on one form of shield fighting. You can find the second part on the same page.

Re blade sharpness, there's a difference between a slicing edge and a cleaving edge. Against an unarmored or lightly-armored target you might be able to get away with the thinner slicing edge, but against a man in armor that's an excellent way to roll the edge or chip it.

As for grasping a live blade, I'd guess that in most combat situations you would be wearing heavy leather gloves at the very least, if not mail (depending on the era), so half-swording or trapping an opponent's sword would be fairly easy. I could see actual barehanded grabbing work if you were to quickly follow with a sword strike before your adversary could pull free.

I'm sure the more knowledgeable members of this forum can give more informed and experienced opinions on these matters, so I will defer in advance to their expertise in the likelihood that I am mistaken.

[Hjolnai]

My understanding of the German longsword tradition is that you don't parry - you make a cut on a line which intercepts your opponent's cut. The difference is that, while blade contact is still made, your own cut creates a genuine threat, and the opponent can't back out of their attack before contact (or your cut will hit them). It has nothing to do with avoiding damaging the sword (and I don't see how you could "use the flat of the blade" as I've seen some people suggest, while still creating a threat).

Disclaimer: My knowledge is filtered from the training of someone else who has read the manuals in the Liechtenauer tradition, not my own readings - so no guarantees.

[Galloglaich]

You do parry in the Liechtenauer tradition; but you dont "just" parry, ideally, the system emphasizes a lot of single -time counters (most of the Versetzen, the Absetzen and so on)

The idea is to sieze the momentum when you are attacked, turn the tables. The Liechtenauer system emphasizes offense more than some of the others but its not kamikaze.

I was the one who posted the video pf a guy cutting tatami and then grabbing the blade ... Its Roland Warzecha of Hammmabourg. I'll have to go find it again.

G

[Rakaydos]

Just jumping back on the dragon race for a second, but wouldnt it be plausable to give the same "bare handed deflection" we've been discussing to the wings, with a proper "gauntlet" wingcap? for complete coverage you would probably lose flight as an option (being unable to open the wing) but woud effectively have 4 hands for fighting.

[warty goblin]

Just jumping back on the dragon race for a second, but wouldnt it be plausable to give the same "bare handed deflection" we've been discussing to the wings, with a proper "gauntlet" wingcap? for complete coverage you would probably lose flight as an option (being unable to open the wing) but woud effectively have 4 hands for fighting.

I think the operative difference is that a person generally grabs a blade in a bind, that is to say when the two blades are actually touching and pretty much stationary. It's not really a deflection so much as it is a grab to force their blade aside so you can hit them. As I said before, my understanding is that this is also done with a very specific grip to prevent the other person from yanking the blade back and cutting your fingers off.

And with the wing thing, what happens when somebody does use a hooked weapon, snags it behind the elbow joint, and gives a good, hard yank? Or winds off of it with a longsword and thrusts to the neck? Is it worth running the risk of that sort of injury for an awkward, offline parry?

[Rakaydos]

I think the operative difference is that a person generally grabs a blade in a bind, that is to say when the two blades are actually touching and pretty much stationary. It's not really a deflection so much as it is a grab to force their blade aside so you can hit them. As I said before, my understanding is that this is also done with a very specific grip to prevent the other person from yanking the blade back and cutting your fingers off.

And with the wing thing, what happens when somebody does use a hooked weapon, snags it behind the elbow joint, and gives a good, hard yank? Or winds off of it with a longsword and thrusts to the neck? Is it worth running the risk of that sort of injury for an awkward, offline parry?

The risk is there whether you are trying to parry or not- if you're trying to get a hooked weapon all the way behind the elbow (or do you mean wrist?) you're already well past the guard, and the creature's 2hander should already be breaking the haft. If it's bit slow, well, congratulations, you got in a powerful blow- if not, you've just lost your primary weapon.

[warty goblin]

The risk is there whether you are trying to parry or not- if you're trying to get a hooked weapon all the way behind the elbow (or do you mean wrist?) you're already well past the guard, and the creature's 2hander should already be breaking the haft. If it's bit slow, well, congratulations, you got in a powerful blow- if not, you've just lost your primary weapon.

I'm not well past the guard if the drake is literally using the wing as its guard. Then all it takes is a flick forward maybe four inches, and a good, sharp, yank. Combine with a decent sidestep and a realignment of the haft and it's a pretty safe move, really. Say strike from the right, twitch the blade forwards, then step back with the left foot while raising the haft and pulling back. End in high guard, ready to thrust to the face. A human's already got the reach advantage given equal length weapons, and all but the most outsized swords are still shorter than most pole-arms.

[Rakaydos]

Sounds like you're talking about the wrist, not the elbow. is that correct?

So youre swinging a halberd in from the side, baiting an upward deflection (elbow high, wrist low and extended to the side) from the wing (as opposed to a blade block, I suppose) then twisting to hook the wrist and yanking it toward you?

Meanwhile the dragon is dropping the elbow and raising the wrist to trap the polearm inside the wing's reach and pulling it inward (also, as part of the same motion, countering your efforts to lift your polearm to get a downward hook by angling the bones you're trying to hook) while the dragon;s blade comes across to break the haft, disarming you in exchange for a ripped membrane and possibly some bone damage to the wing.

Does this seem reasonable? It requires technical skill on the part of the dragon, which would be part of martial training, but seems well within the dragons range of motion. And bones can heal, whereas it is rather hard to heel from what the two-handed blade will do to the disarmed human.

EDIT: Or, for tht matter, simply stepping foreward with the hook, and running the polearm-user through with a greatsword. Advantage going to the person with multiple aveneues of attack.

[warty goblin]

Sounds like you're talking about the wrist, not the elbow. is that correct?

Yeah, sorry my bad.

So youre swinging a halberd in from the side, baiting an upward deflection (elbow high, wrist low and extended to the side) from the wing (as opposed to a blade block, I suppose) then twisting to hook the wrist and yanking it toward you?

I'd figure I'm probably swinging the thing at the drake's head. The question is what I do in the event the blow does not connect. I could even be doing this through a bind, so the head of my weapon is in contact with the drake's blade.

Meanwhile the dragon is dropping the elbow and raising the wrist to trap the polearm inside the wing's reach and pulling it inward (also, as part of the same motion, countering your efforts to lift your polearm to get a downward hook by angling the bones you're trying to hook) while the dragon;s blade comes across to break the haft, disarming you in exchange for a ripped membrane and possibly some bone damage to the wing.

Halberd hafts are tough things. Decent hardwood shod in iron is very tough; hell even just decent hardwood can be mighty hard to break. You aren't going to shatter one with an offhand tap, it takes some legit force. Hence the step to the side, it takes the human effectively off the dragon's line of attack while keeping their weapon in line to threaten neck, head or other opening. Particularly since a human will be able to step to the side much faster than a long creature with its mass all spread out will be able to rotate to match.

The pull and the rotation in this move is also powered by the muscles of the back, shoulders and hips. All the big ones in other words. The haft realignment can effectively bind a sword as well.

And nobody in their right mind trades some bone damage for maybe breaking an enemy's weapon, particularly if that bone damage is to their primary locomotion system. Hell, I broke my collarbone a decade or so ago, and it's only in the last two years that my left shoulder has regained the same strength as the right. Again, nobody takes hits they can escape by other means.

Does this seem reasonable? It requires technical skill on the part of the dragon, which would be part of martial training, but seems well within the dragons range of motion. And bones can heal, whereas it is rather hard to heel from what the two-handed blade will do to the disarmed human.

Being disarmed is not the end of the world. Then it's just time to pull a dagger, get in close and go for the eyes.

EDIT: Or, for tht matter, simply stepping foreward with the hook, and running the polearm-user through with a greatsword. Advantage going to the person with multiple aveneues of attack.

That's why the sidestep. It's hard to attack effectively when one's weapon is not in line to do so.

And if the advantage went to the person with multiple avenues of attack, everybody would just run around with weapons in each hand. They don't, because aside from some very specific contexts, it's better to have one serious method of assault than a lot of piddly ones. I've fought people with akimbo swords using just one of my own. I've frequently beat them, because the second blade restricts almost as many options as it gives.

[Rakaydos]

That's why the sidestep. It's hard to attack effectively when one's weapon is not in line to do so.

Quick point here- while any kind of gross rotation would be difficult to do quickly, minor reorentations can be managed by tail-shifts- that is, lashing sideways with the tail to pull the forebody into a new facing momentarlly, limited by the beast's ability to maintain balance.

For that matter, if the wing is folded at the wrist as tightly as most bats seem to be while walking, actually catching the fingers would take some doing- you are far more likely to "merely" tear the membrane (which would NOT be the primary movement for "Heavy knight armor" warriors) and possibly hook the forearm. Note that, while damaging, you are also giving the dragon a meassure of control over your weapon's head.

Perhaps I'm having problems with visualization, but I'm having a hard time imagining how you're binding both the blade and the wing with the same weapon head.

(though perhaps we should take this elsewhere- though interesting to me, it seems like few others are contributing to this discussion, and we are drowning out other conversations)

[Raum]

<from the previous thread>
Is there something different between how sails work and how bird wings work? I would put it down to birds being fully in thte air vs. ships being in the water while using the wind for propulsion, but then agai nthat is why i bring it up - what is going on and why?

The first difference which springs to mind is the direction of forces involved. Lift from a bird's wing will push it up where the equivalent "lift" from a sail pushes the ship forward.

A ship sailing down wind in a 5mph breeze has less relative wind speed as it approaches 5mph. If it ever hit exactly 5mph it would feel like you're in calm weather. (Notably this can make sailors underestimate wind speeds and potentially cause problems when turning.)

A ship sailing across the wind works in a state of tension between two fluid systems - the water supporting it while resisting hull movement and the air moving across the ship both pushing on the sail and creating a low pressure area in front of the sail to pull. Your speed across the wind doesn't affect the 'pushing' vector (relative wind speed is still 5mph) but increasing speed does increase the 'lift' factor (wind speed across the belled face of your sail is faster). If your hull had zero resistance to forward movement your forward speed would approach infinity - though other factors also apply (you will reach a point where air resistance in front of you presses your sail back in - at least for non-wing sails). In any case I'm oversimplifying.

Here are a couple of sites with the technical explanations:
- Points of Sail diagram
- Physics of Sailing
- Windsurf physics
- Sail flow analysis

Love the Mythbusters. But have been bothered by their "proving" that splinters from cannon balls weren't the danger they are often perceived to be.

Don't think I've seen that episode. However, wood is resilient. It's going to bend around the penetration point and most will snap back into place. This is part of why sinking from cannon fire alone (pre-explosive rounds) was relatively uncommon - the resulting holes simple weren't that big. As long as the splinters are small, they're not going to penetrate much.

[Mr. Mask]

I'll bring up armour penetration.

If you had someone rigid, lying on the ground for example: How well could you puncture heavy mail or plate armours with an acute sword point, a spear, or the dague or queue of a poleaxe?

This is something exaggerated in fiction, but I don't truly know how much it is exaggerated.

[Maeglin_Dubh]

Also remember that in longsword (especially armored longsword in the Meyer [and I believe also Lichtenauer and Talhoffer traditions]) the blade is not the only active part of the sword. Quillons and pommel are all considered fair play in terms of making your opponent non-viable.

I'll bring up armour penetration.

If you had someone rigid, lying on the ground for example: How well could you puncture heavy mail or plate armours with an acute sword point, a spear, or the dague or queue of a poleaxe?

This is something exaggerated in fiction, but I don't truly know how much it is exaggerated.

My understanding is that you tried, whenever possible, to go for gaps. And even in what D&D would call fullplate, there were gaps. And the acute points you're talking about could, in some cases, exploit them.

Rondel daggers are dandy for this, being basically a heavy icepick.

As a for instance, if I'm in plate, fighting a man in plate, and he's on the ground, and I'm not, I'm going to try to stab his visor, or his armpit, or his crotch, since these are all places where armor often has necessary gaps for articulation (also vision).

[oudeis]

I'll bring up armour penetration.

If you had someone rigid, lying on the ground for example: How well could you puncture heavy mail or plate armours with an acute sword point, a spear, or the dague or queue of a poleaxe?

This is something exaggerated in fiction, but I don't truly know how much it is exaggerated.

A helpless target wearing mail- I'm presuming you mean chain armor here- would be vulnerable to to a thrust, especially from a weapon designed to counter such armor like the ones you mentioned or an awl-pike. You can find lots of videos on youtube where the resistance of riveted mail to thrusting attacks is put to the test. From the ones that I've seen, it seems to take a two-handed attack at an advantageous angle with a narrow-pointed weapon to effect any meaningful penetration. One attack I saw with a longsword wielded in a half-sword grip penetrated several centimeters but the blade got caught in the links. While the thrust probably would have gone through a gambeson and inflicted a serious wound the attacker would have effectively disarmed himself.

As for plate armor, actually penetrating one of the pieces with a hand-held weapon was incredibly difficult. Even when dealing with an immobile target, you are striking against polished, precisely curved pieces of metal that are specifically designed to deflect or turn attacks. Even a weapon designed to penetrate armor like a poleaxe or a bec-de-corbin would have to strike at the right place and the correct angle to inflict a fatal wound.

[Brother Oni]

One attack I saw with a longsword wielded in a half-sword grip penetrated several centimeters but the blade got caught in the links. While the thrust probably would have gone through a gambeson and inflicted a serious wound the attacker would have effectively disarmed himself.

Typically with a kill stroke like that, you'd twist to both widen the wound and to aid you in retrieving your weapon.

I agree that between the armour and a resisting victim, you'd probably be disarmed in combat.

Even when dealing with an immobile target, you are striking against polished, precisely curved pieces of metal that are specifically designed to deflect or turn attacks. Even a weapon designed to penetrate armor like a poleaxe or a bec-de-corbin would have to strike at the right place and the correct angle to inflict a fatal wound.

I think you're over-estimating the victim here. With a helpless target, setting the tip of your blade over a weak spot (like between the gorget and the helmet) and leaning down is just as effective.

Weapons don't have to hit with force to kill, just penetrate. Pushing a dagger into someone's neck may be slower and harder than stabbing them, but it doesn't it make them any less dead.

As Maeglin_Dubh also said, this is why soldiers carried thin stiletto-like daggers for killing/capturing floored armoured opponents.