Knife Reaches

[Sindri]

Unlike most broadswords (the katana being the exception) where thrust reach is greater than or equal to swing reach knives have swing reach greater than or equal to thrust reach.

At first it seems obvious that thrust reach should at least equal swing reach but upon reflection it becomes apparent that once you take into account the requirement to actually solidly pierce the opponent rather than poke them swing reach could be longer than thrust reach and that a sufficiently curved blade could cause you to lose effective reach. It still seems kind of odd that the method of attacking that gives you the most reach changes as the length of a blade increases, that there aren't any other stats for katana style swords (mechanically a swing reach 2, thrust reach 1,2 suggests itself), and how small a fraction of knife and main-gauche weapons have thrust reach 1.

It seems like there is room to extrapolate a main-gauche knife with reach 1 swing cutting and reach 1 thrust impaling from the example of the jutte and sai. Possibly with higher damage. Though reach 1 for thrusting and swinging for jutte and sai seems a bit odd compared to a long knife's listed length. What do you think?

Why does a main-gauche's thrust reach change to C when used with knife skill and a long knife's swing reach change to 1 when used with shortsword skill?

[Curmudgeon]

Do you have a reference source for this, please?

All I have that seems to be relevant is Basic Set, 4th Ed, which doesn't list jitte/sai or main-gauche, except as skills under melee weapon (B208-209). The sections on Reach (B269, B369 & B388) don't indicate that the reach of a specific weapon changes depending on the specific skill it is being used with. Interestingly, neither a line for Jitte/Sai or Main-Gauche skills appears in the Melee Weapon Table (B271-274).

Going solely by what appears in the Basic Set, I'm inclined to think that the differences for reach for swing and thrust damage are inherent to the definitions of the weapon lengths involved (B208-209) rather than the skill involved.

Thrust damage, in the case of knives and swords, results from a stabbing motion using the tip to start the penetration. The thrust action is limited by the length of your arm, you can start your weapon back from your shoulder and extend it the full length of your arm. Coupled with your hand overlapping the hilt's length, the range of motion is for most people a bit less than a yard, which is below the point where GURPS takes notice of it. Hence, thrusting reach is always limited to the extent of the arm plus the length of the weapon from the grip. Generally, for any weapon longer than two feet, the weapon length becomes the limiting factor for reach in combat. For a weapon such as a knife where the length of the blade is significantly less than the length of your arm, the length of your arm becomes the limiting factor and you can pull your arm in closer to thrust from closer, which doesn't make a great deal of difference from the view of the table, beyond letting you use a knife to thrust in Close Combat.

Swing damage, on the other hand, is using the sharpened edge, rather than the tip of the blade, and moving the edge through an arc so that anywhere along the sharpened edge can cause damage. The majority of the blade's edge is sharpened and it's this sharpened length that does the damage and in general, the length of the weapon, rather than the length of your arm becomes the limiting factor for the same reason that arm length was the limiting factor for thrust. You can only move the dangerous part of the weapon the length of your arm, so it's dangerous over the whole reach. Knives, be definition (B208), are under a foot long overall and the blade is therefore less than that, so the length of the arm makes up the majority of the reach. Because you can pull the blade back more than its own length, you can swing from much closer than would be possible with a longer weapon.

I would think that a main-gauche's reach would allow it to use C when using the knife skill because the main-gauche's principal use is as a fencing weapon where it is being used against longer weapons, so it is being used at closer to its maximum reach. Knives, on the other hand, are one of the few weapons that can be used in Close Combat because the blade is short enough to be used in circumstances where you and your opponent are an arm's length, or less, apart. OTOH, shortsword skill is for use with blades 1-2 feet in length (B209) and knives are for blades 1 foot or less in length (B208), so if a large knife can be used with shortsword skill and get an increased reach, it must be right on the cusp and be a 1 foot long weapon.

YMMV.

[Sindri]

Originally Posted by Curmudgeon

Do you have a reference source for this, please?

All I have that seems to be relevant is Basic Set, 4th Ed, which doesn't list jitte/sai or main-gauche, except as skills under melee weapon (B208-209). The sections on Reach (B269, B369 & B388) don't indicate that the reach of a specific weapon changes depending on the specific skill it is being used with. Interestingly, neither a line for Jitte/Sai or Main-Gauche skills appears in the Melee Weapon Table (B271-274).

Yes, the most recent book containing weapon tables is Low-Tech so that's what I'm working from. Honestly I rarely read Basic's weapon tables anymore but the large knife and small knife maintain their greater swing reach in Basic. Martial Arts appears to be the same as Low-Tech for everything I've mentioned.

Originally Posted by Curmudgeon

Going solely by what appears in the Basic Set, I'm inclined to think that the differences for reach for swing and thrust damage are inherent to the definitions of the weapon lengths involved (B208-209) rather than the skill involved.

This is, however not true in later books. Reach is normally preserved and when it isn't it is usually due to things like a tonfa's multiple ways of use. The main-gauche and long knife changing their reach based on skills seemed weird which is why I asked.

Originally Posted by Curmudgeon

Thrust damage, in the case of knives and swords, results from a stabbing motion using the tip to start the penetration. The thrust action is limited by the length of your arm, you can start your weapon back from your shoulder and extend it the full length of your arm. Coupled with your hand overlapping the hilt's length, the range of motion is for most people a bit less than a yard, which is below the point where GURPS takes notice of it. Hence, thrusting reach is always limited to the extent of the arm plus the length of the weapon from the grip. Generally, for any weapon longer than two feet, the weapon length becomes the limiting factor for reach in combat. For a weapon such as a knife where the length of the blade is significantly less than the length of your arm, the length of your arm becomes the limiting factor and you can pull your arm in closer to thrust from closer, which doesn't make a great deal of difference from the view of the table, beyond letting you use a knife to thrust in Close Combat.

Swing damage, on the other hand, is using the sharpened edge, rather than the tip of the blade, and moving the edge through an arc so that anywhere along the sharpened edge can cause damage. The majority of the blade's edge is sharpened and it's this sharpened length that does the damage and in general, the length of the weapon, rather than the length of your arm becomes the limiting factor for the same reason that arm length was the limiting factor for thrust. You can only move the dangerous part of the weapon the length of your arm, so it's dangerous over the whole reach. Knives, be definition (B208), are under a foot long overall and the blade is therefore less than that, so the length of the arm makes up the majority of the reach. Because you can pull the blade back more than its own length, you can swing from much closer than would be possible with a longer weapon.

Limiting factor is not an applicable term here. Arm reach and weapon length are additive in both reality and gurps. How much one can contribute to your reach is not limited by the other. The length of a weapon will limit how close you can strike (or rather how comfortably you can strike at closer reaches as gurps eventually represented) but this is already represented in gurps. I never asked "why can knives strike at reach C".

Originally Posted by Curmudgeon

I would think that a main-gauche's reach would allow it to use C when using the knife skill because the main-gauche's principal use is as a fencing weapon where it is being used against longer weapons, so it is being used at closer to its maximum reach. Knives, on the other hand, are one of the few weapons that can be used in Close Combat because the blade is short enough to be used in circumstances where you and your opponent are an arm's length, or less, apart.

A main-gauche as a physical weapon is the same thing whether used with the main-gauche skill or knife skill. It's length doesn't change. Reach stats are supposed to indicate the weapon's capabilities with the listed means of use not what the wielder is most used to using. The only thing I can think of to explain the main-gauche's changing reach is that the fencing stance associated with it pushed it into a new reach. Which is fair I guess? But I don't think that changing to a fencing skill ever does that again.

Originally Posted by Curmudgeon

OTOH, shortsword skill is for use with blades 1-2 feet in length (B209) and knives are for blades 1 foot or less in length (B208), so if a large knife can be used with shortsword skill and get an increased reach, it must be right on the cusp and be a 1 foot long weapon.

YMMV.

The long knife which is not the same thing as a large knife can be used with shortsword skill but this doesn't offer an increased reach, just loss of reach C in one of it's modes. The long knife has a total length 'between 15" and 23"' which is rather odd concerning both Basic's old definition of knives and shortswords and the listed length range of shortswords but it's a known oddity.

[Balor Patch]

Giving the usual level of GURPS editing these are probably WAD, but they all do feel odd to me:

1) Long Knife has swing reach C,1 as knife, 1 as shortsword.

2) Main-Gauche has thrust reach C as knife, C,1 as main-gauche.

3) Rodel Dagger and Stiletto have parry -1 as knife, 0 as main-guache.

4) All weapons used with a fencing skill gain parry F and lose it when employed with a different skill. It should be part of the skill discription, not the weapon.

I only looked at the knife, shortsword, and various fencing skills but don't know of any other 1H weapons that change reach or parry between modes with similar thr/sw.

[Sindri]

Originally Posted by Balor Patch

Giving the usual level of GURPS editing these are probably WAD, but they all do feel odd to me:

Yeah I'd be really surprised if these were actual errors that nobody caught since Martial Arts.

Originally Posted by Balor Patch

3) Rodel Dagger and Stiletto have parry -1 as knife, 0 as main-guache.

I noticed the rondel dagger and stiletto as well but I can accept that as a a bonus thrown in with fencing parry in their case. It's sort of odd that the rondel has it at all though. I would have thought it would be one that could have a 0 parry.

Originally Posted by Balor Patch

4) All weapons used with a fencing skill gain parry F and lose it when employed with a different skill. It should be part of the skill discription, not the weapon.

Unfortunately GURPS weapon entries have had a tendency to lean towards ease to use rather than a scrupulous and iron seperation between the nature of a weapon and what a skill gives you. It's made notable improvements over time though.