Visible Warrior Invisible Sword
 

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Is there any precedent for foes' defense rolls being penalised against an invisible sword wielded by a normal opacity foe (ideally GURPS 4e)? (to the extreme, should not a 3-yard invisible polearm should impose /some/ penalty to user's defense?) This is in context of GURPS Magic 4e "Invisiblity" p. M114...


I) BASIC indicates explicitly if both the foe and weapon are invisible defenders roll at -4. (B394)


II Toward the opposite case (invisible warrior, visible sword):
With a visible warrior wielding a sword, someone striking /at/ the weapon: striking at a broadsword is -4 (B400)

M63 -5 to strike /at/ a broadsword... wielded "As if by an invisible foe"

So more or less -1 if the wielder is invisible (I suppose you could read from the wielder where it is going next).

Re: Visible Warrior Invisible Sword
 

I don't think you can do simple arithmetic on these modifiers and expect them to reflect what's going on.

I don't know if something has been published, but assuming a visible combatant with an invisible weapon that is known to be there, I'd say it probably warrants a -1 or -2 to active defense rolls against the invisible weapon. Probably -2 if you've never fought against such a weapon before, -1 if you have. I'd probably impose a -2 familiarity penalty on the wielder until they had some practice in it — familiarity doesn't usually apply to swords, but it's got to be hard to get the hang of using an invisible weapon.

Re: Visible Warrior Invisible Sword
 

I might do something like a penalty of -(1+reach). It makes sense to me that a longer weapon would be harder to deal with. Maybe even worse with a flexible weapon: I can imagine an invisible whip being incredibly difficult to predict.

Re: Visible Warrior Invisible Sword
 

Realistically, the business end of a weapon held by a competent warrior moves too quickly for a human to watch and react to in any meaningful way. Even just watching the bare hands of a competent unarmed warrior won't give you enough reaction time to accomplish much in the way of defense. So, you watch the arms - upper arm and shoulder, mostly. So, an invisible weapon of known length isn't as big of a problem as it would first appear. Even if length is unknown, at best this probably just means your foe can get you to "waste" a defense by making an attack from outside of his/her weapon's actual reach.

With that said, there are rules for a known but partially-concealed weapon to impose a penalty to defense. If you have a weapon in a reverse grip, or have it hidden behind a shield or similar, then if you use Deceptive Attack, it imposes a further -1 to defense. An invisible weapon should therefore do at least that, and I can see increasing this to -2... but only if you're also imposing a -2 or worse to the foe's defense via Deceptive Attack. So, a total of -2 to defense for a -2 to hit (-1 to defense for DA, -1 for obscured weapon), -4 to defense for a -4 to hit (-2 to defense for DA, -1 for obscured weapon, further -1 for outright-invisible weapon), then a further -1 to defense for every additional -2 to hit. If you want to make the first few bits be at -1 to defense for every -1 to hit, I wouldn't object. If you've built the weapon as a power, I'd offhand call Obscured Weapon (further -1 to defense if using DA) a +20% modifier, Invisible Weapon (up to a further -2 to defense if using DA) a +40% modifier; the first probably also requires Low Signature, while the latter probably also requires No Signature.

Re: Visible Warrior Invisible Sword
 

I think you could make a good case for -2, which is often the penalty for attacks you can't quite see clearly (back attacks with peripheral vision for example), but there are cases of -1 in the rules also (e.g. Mystic Mist) or even no penalty (dodging bullets).

I actually think I'd go with either -4 (you have no reason to suspect that guy there is armed and are effectively totally surprised) or -0 (you know the foe has an invisible weapon - you are generally allowed to defend against somebody you are sure will attack you but you don't know exactly when or how at no penalty (that gunfire, or when he fast draws a weapon) and you are no worse off than that.

Re: Visible Warrior Invisible Sword
 

The Stealthy Attack imbuement gives -2 to Perceptions to notice it. So I'd probably say that BUT the first time they are attacked by an invisible weapon I would totally say "No defense. Sorry."

Re: Visible Warrior Invisible Sword
 

The key word in Varyon's post is "known". Melee attacks are often "games of inches" where a successful attacker gets within weapon range for just long enough to launch a blow and 2-3 inches of weapon length can mean the difference between a kill or a miss.

Unless the defender has a very good idea of how long their opponent's weapon is and what sort of weapon it is, they're going to be at a serious initial disadvantage. This is particularly true for long-range thrusting weapons like spears, since the moves used to thrust a 2-yard spear are about the same as those used to handle a 4-yard spear.

I'd increase penalties by 50% vs. a completely unknown weapon's first attack (whether hit or miss), then allow a Tactics or Per-based roll against best Melee Weapon skill per attack to figure out what you're up against. A situation like this would also be a good time to back off and choose the Evaluate maneuver, which might give +2 to your roll.

Success means you suss out exactly what you're dealing with (e.g., "Thrusting Broadsword, about 40" long"). Failure by 1-2 might give general information ("Some sort of one-handed sword.")

Arguably, you could also boost bonuses for Deceptive Attacks, since you can pantomime using one type of weapon while actually setting up to use a very different weapon.

Re: Visible Warrior Invisible Sword
 

Just as a point of reference, Invisible Weapons in DFRPG (from Magic Items 1, p7) give a -2 to defend for the first attack only, with the defender being ready for it afterward. That's a bit generous to the defense IMO, but there you are.

Re: Visible Warrior Invisible Sword
 

This point suggests that attacker also has the burden of learning how to fight with an invisible weapon to make proper use of that advantage. You don't just pick up an invisible sword and fight exactly the way you used to. Perhaps, in game terms, it should be a Technique or Familiarity to train to get that -2 to the enemy's defense.

Re: Visible Warrior Invisible Sword
 

Back in 3e, Magic Items included rules for an invisible sword. To quote:

"When fighting
against an invisible sword, the defender is normally at a -1 to all
active defenses (-3 if the defender's primary weapon skill is 10
or less, no minus if his skill is 15 or better - the best fighters react
to cues from their opponent's face and body, not his weapon)."

-GURPS Magic Items 1, p.93

Re: Visible Warrior Invisible Sword
 

Christopher Rice has rules for the "Transparent Blade" technique for the Psi Sword ability in Pyramid 3/69. I'm surprised he didn't mention it! Can it be that he doesn't remember all the articles he's written?

Re: Visible Warrior Invisible Sword
 

+1. As a longtime hockey goaltender, you just don't watch the stick or puck in any kind of traffic; you're screwed if you do. You key off of the shoulders -- the flex gives you a fraction of a second warning as to timing and angle. And the same goes for swordfighting: I'd always watch the eyes and upper arms, because that gives you what they call a "precede."

But this is also a veteran thing -- it's something you learn over long experience, and furthermore different people have different "precedes," and successful one-on-one fighters get good at masking their intentions. My own gambit was to let my eyes go slightly unfocused, gazing at a point over my foe's shoulder ... it was pretty successful at disguising where I was going to strike next.

So I'd look for a fairly strong penalty, and halve that when it comes to experienced fighters, especially ones with skills/advantages pertaining to evaluation: Combat Reflexes, Style Familiarity, that sort of thing. I would NOT eliminate the penalty altogether, as that Magic Items cite suggests: for an experienced fighter, defense is often gauged in inches or fractions of inches, and not being able to tell the actual pitch of a weapon by 10-15+ degrees is going to screw with that.

Re: Visible Warrior Invisible Sword
 

Many thanks everyone!
This is essentially what I was looking for. (I was envisaging something about rolling against your best weapon skill to read the foe).

Re: Visible Warrior Invisible Sword
 

Hey! It's crowded in the ol noggin. Too much stuff in my head. I can't remember ALL of it. >__>

Re: Visible Warrior Invisible Sword
 

I'm not sure I'd allow no negatives at all. It's very much about other cues, as several have mentioned, but know *exactly* the size, shape, and movement of the weapon helps, and not knowing has to make it harder.

I'd probably make it -3 default, -5 if defender is below skill 10, and -2 with skill 15+ and -1 at skill 20+ for parries and dodges. Blocks I'd make one better because there's more tolerance in position when putting a shield in the way.

That's just my take. Most importantly, I will now need to unleash some invisible weapons against my PCs!

Re: Visible Warrior Invisible Sword
 

I wouldn't go as bad as -5, even for the untrained, given that a completely invisible foe is defended against at only -4, and making the non-weapon parts of him visible shouldn't make defending harder.

If I were going to get complicated, I might be tempted to base the penalty on relative skill level (DX-1, DX+3, etc.) rather than absolute skill level, since, while training and experience (i.e., character points spent on the skill) may well let you read an opponent's attack from their body, I don't see raw dexterity helping very much- this is probably something where a seasoned veteran has an advantage over a tyro however talented.

EDIT: If I were basing the penalties on defender skill in any way, I would certainly use the highest combat skill to calculate them irrespective of which weapon is currently being wielded. If training in swordsmanship includes skill in reading an opponent, this skill won't go away just because one is forced to drop the sword and fight with a knife.

Re: Visible Warrior Invisible Sword
 

That's a fair point, but I think only - 4 to defend against a completely invisible foe is too light without mitigating advantages or skills.

Re: Visible Warrior Invisible Sword
 

With GURPS assumptions and levels of resolution, I think just letting the fact that higher skill means higher defense stand works fine here - part of why low-skill combatants (and those working off of defaults) have a poor defense is because they try to follow the hands and weapons and the like. Alternatively, watching the shoulders and the like is why characters with Combat Reflexes get a +1 to all defenses (because, honestly, knowing what to watch on the enemy should improve all of your defenses, not just Parrying with your favorite weapon type).

And I think calling it a "veteran thing" is overstating the point. This is what I did back when I practiced Taekwondo, and I certainly wouldn't deign to call myself a veteran, I just had some experienced people teach me to do so. If you're learning it all by yourself, sure, you could say you may not come up with it until you've reached a certain level of skill - but humans typically don't learn stuff like this on their own, they have someone to teach them.

That said, if you want some Harsh Realism optional rules here, I'd still use my suggestion (up to an additional -2 to defense when using Deceptive Attack), and further state that any character that doesn't have any melee combat skills at DX+2 or higher is also at an additional -2 to defend against such weapons, regardless of if the attacker opts for a Deceptive Attack or not. Optionally, this is only a -1 at DX+1 (so at DX or lower, you're at -2; at DX+1, you're at -1; at DX+2 or higher, you're at +0). As a corollary, as others have noted, the wielder of an invisible weapon needs some training before he or she can use it effectively. This is simply a Familiarity, so treat it as such (I think that means either 4 or 8 hours to become proficient). As a further option, if the character has never used this particular type of weapon (say, it's a Large Falchion, and the character lacks Familiarity with that), double the amount of time needed to become proficient; if the character can see the weapon but enemies cannot, halve it.

Re: Visible Warrior Invisible Sword
 

this is probably a broader issue too

like say for example your ally is grappling an invisible foe: you'd probably have a better idea of where to attack to hit that invisible foe

Re: Visible Warrior Invisible Sword
 

Yep. I think the GM needs to assess the situation, perhaps even on a turn by turn basis, to review modifiers.

Re: Visible Warrior Invisible Sword
 

I agree that somewhere between -4 (they step into measure and attack, you don't know what weapon they have or how long it is) and +0 (you are in close combat with them) seems reasonable.

In real fighting against things which move too fast to see and respond to such as spear thrusts, a common tactic is finding the sword: put your weapon between your body and their weapon, close to it or touching and with an advantage in leverage, so you can feel what they are going to do. If I ever reworked the weapons skills, I would probably have a class of skills like Rapier and Spear which assume that you lead with the weapon point-in-line. Those skills would probably have lower penalties to defend against this hypothetical invisible weapon.

Re: Visible Warrior Invisible Sword
 

Any normal person would be more likely to blow at least a round staring, and muttering "What the hell is going on there?"

Re: Visible Warrior Invisible Sword
 

Unless you are informed in advanced about the invisible person or weapon, you'll have to use the surprise mechanics.

Re: Visible Warrior Invisible Sword
 

In a campaign that allows a bit of sillyness, I would introduce the invisible swordsman by reputation. Then have the PCs meet him and only then realize he isn't the "invisible (swordsman)" but the "(invisible swords)man".