Slicing vs Hacking with a Sword

[SuedodeuS]

This is inspired by this thread and the discussion of katana vs broadsword therein. I originally wrote this as a reply, then realized it should probably be a topic of its own.

The way I understand it, the curvature of the katana (and other weapons, like shamshirs and the like) makes it so that, almost regardless of the way you are wielding it, it is used for slicing, whereas straighter swords (like the European broadswords) are used more for hacking. Slicing is excellent at causing damage, but said damage is entirely cutting - if you fail to cut through the armor, the attack basically does nothing. Hacking, on the other hand, isn't quite as good at damaging soft tissue (although it does that quite well), but can "get through" (in terms of blunt trauma) armor much more readily. When one considers how resistant steel is to cutting, it seems clear - slicing is best against unarmored or lightly armored foes, while hacking is best against more heavily armored foes.

Assuming the above is true (and it certainly may not be), there needs to be a way to represent it in GURPS. Rumor has it that Low-Tech is going to have a new optional rule for cutting vs armor. Simply put, cutting damage that beats DR, but doesn't double it, fails to actually cut through and thus the damage transmitted is actually crushing. So, against DR 5, 4 damage does nothing, 7 damage does 2 crushing, and 12 damage does either 7 cutting or 5 crushing and 2 cutting. We'll have to wait on the books to know which, although I suspect it's the former and will be working based on this suspicion. We'll use this rule to build the slicing vs hacking dichotomy, and we'll be assuming that the rule is based on some middle ground between the two. The normal DR value (5 in the above case) will be called minDR, the DR value after which damage becomes cutting (10 above) will be called maxDR.

Slicing: Slicing is ideal for causing damage, but it is terrible at transmitting blunt trauma. When slicing, basic damage is increased by +2, or +1/die, whichever is higher. minDR becomes equal to one less than normal maxDR, while maxDR remains unchanged. Highly-curved weapons, like katanas and shamshirs, slice by default (although their stat lines do not include this additional damage). At the GM's option, a straight-edged weapon (like a European broadsword) can be used to slice. This is a Hard Technique, defaulting to Skill-3. Most Axe/Mace weapons may be incapable of slicing.

Hacking: Hacking is extremely good at transmitting blunt trauma through armor. minDR is reduced by 20% (reduce by at least 1), while maxDR is increased by 20% (increase by at least 2). Straight-edged swords and most Axe/Mace weapons hack by default. At the GM's option, a curved weapon (like a katana) can be used to hack. This is a Hard Technique, defaulting to Skill-3.

Example: We'll assume an ST 12 character using Two-Handed Sword. With a katana or bastard sword, he would normally do 1d+4 cut on a swing. Using the optional rule above, the katana (a slicing weapon) does 1d+6, while the bastard sword (a hacking weapon) still only does 1d+4. Against DR 5, however, the katana wielder must deal 10 damage to do 1 cr, or more than 10 to do some cutting. The wielder of the bastard sword, on the other hand, starts dealing crushing damage on a roll of 5 or higher - although he must breach DR 12 (impossible without an additional damage bonus from somewhere) before he starts doing cutting damage. Let's look at the breakdown of probabilities, converting the adds to dice.

Katana (2d+2)
Probability	Damage	Injury
1/36		4	0
2/36		5	0
3/36		6	0
4/36		7	0
5/36		8	0
6/36		9	0
5/36		10	1
4/36		11	3
3/36		12	4
2/36		13	6
1/36		14	7
AVERAGE			1.333...

Bastard Sword (2d)
Probability	Damage	Injury
1/36		2	0
2/36		3	0
3/36		4	0
4/36		5	1
5/36		6	2
6/36		7	3
5/36		8	4
4/36		9	5
3/36		10	6
2/36		11	7
1/36		12	8
AVERAGE			3.111...

As can be seen, hacking outperforms slicing against armor but (as seen by the basic damage), slicing outperforms hacking against unarmored foes. I also did some more probabilities, and in this case (2d+2 vs 2d), slicing outperforms hacking up through DR 3, after which point hacking is superior. An oddity is that slicing actually outperforms hacking more at DR 2 than at DR 1, as a result of hacking reducing DR 1 to minDR 0. As is also visible, investing in the Slice or Hack Technique can be quite beneficial, as one can Slice against lightly armored foes and Hack against those with heavier armor.

Math: The Slicing Technique gets +2 damage (or +1/die) for -4. It has a special drawback - reduced armor penetration - that gives it a +1. This gives a total of -3. For the Hacking Technique, I simply assumed that hacking with a slicing weapon would be about as difficult as slicing with a hacking weapon. This implies that the improved performance against armor for hacking is worth a -7 (as the damage reduction gives a +4).


Note that these rules are in no way play-tested, and may therefore be unbalanced. They are also in no real way reality-checked, meaning they may greatly overestimate the difference between slicing and hacking (although this may be perfectly appropriate for a cinematic campaign).

What does the hive-mind think?

EDIT: As an alternative option, if you don't want to use the min/maxDR system, then Hacking functions just like normal Cutting, while Slicing gives +1/die (or +2) to damage and reduces armor divisor by one step (generally meaning it becomes 0.5). This should give comparable results.

EDIT2: Based upon further evidence, this system should be considered Cinematic. At the GM's option, curved weapons can be considered as defaulting to Hacking, in which case Slice is simply a Technique any sword can use. If you wish to maintain ethnic badassery, state that Slice is at a lesser penalty (say, -2 instead of -3), or perhaps no penalty at all, when using a curved sword.