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.