Visible Warrior Invisible Sword

[Eric Funk]

Greetings GURPS Forums

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).

[Stormcrow]

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.

[RyanW]

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.

[Varyon]

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.

[malloyd]

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.

[Christopher R. Rice]

Originally Posted by Eric Funk

Greetings GURPS Forums

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).

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."

[Pursuivant]

Originally Posted by Varyon

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.

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.

[Not another shrubbery]

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.

[Anaraxes]

Originally Posted by Varyon

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.

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.

[ravenfish]

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