Bridge battle

Game design musing: Simplifying ST-based thrust and swing damage (GURPS)

Here’s a small simplification GURPS could make: Replace the two damage scores (thrust and swing) attached to ST with one damage score.

Huh? You mean do away with GURPS’ distinctive difference between a weapon’s swing and thrust damage scores? 

No, nothing of the sort! That thrust-vs-swing distinction adds fun considerations to the choice and use of weapons. It’s one of my favorite features of the game’s combat system, right up there with defense rolls. Let’s keep it!

But I think the game could remove the small complication of two damage scores if it wanted – not from combat, but from character stats. 

I’ve made mention of this somewhere in the past, have had a few conversations, and have seen some mentions (and misunderstandings) of it here and there. But I think I’ve yet to bore site visitors with the idea. For the curious and just for the giggles, let me lay out here what I mean by doing away with two character stats for damage, in the form of responses to imaginary questions. (Note: Any weapon stats use newer values from Low-Tech and DFRPG, not Basic Set.)

“Sigh. So what’s the big idea this time?”

Small idea. Very small. For the tinkerers:

In GURPS, characters deal muscle-based hurt through a ST-based damage score, which gets modified for the weapon used or other factors. That’s no different from countless other RPGs. GURPS adds one twist, though: every ST score specifies two of these base damage rolls, one for use with a thrust weapon (or punch, kick, bite, etc.) and one for use with a swung weapon.

It works like this:

  • A PC with ST 10 delivers a base 1d-2 damage with a thrust attack (“thr 1d-2 dam”) or a base 1d damage with a swung attack (“sw 1d dam”).
  • A broadsword deals thr+2 impaling damage or sw+1 cutting damage.
  • The PC’s damage with the sword becomes thr 1d imp and sw 1d+1 cut.

Fine. But we could do this instead:

  • A PC with ST 10 delivers a base 1d-2 damage.
  • A broadsword deals that base+2 impaling damage with a thrust attack or that base+3 cutting damage with a swung attack.
  • The PC’s damage with the sword becomes thr 1d imp and sw 1d+1 cut.

That’s all. Same result, but working with one less stat.

“Why is that even an idea?”

Well, it seems a bit needless to give a character a ST-based swing damage score, when a) the character can’t even use this damage score without a weapon in hand, and b) as soon as the character does pick up a weapon, the weapon goes and changes the damage score anyway.

If you want to nitpick, that ST-based swing damage score comes across as an unnecessary middleman.

“So… just move the thrust-vs-swing damage difference entirely into the weapon’s swing damage add?”

Yes. We could take the RAW approach of “we have this base dam for a thrust, to which we add this amount for the weapon; we have that base dam for a swing, to which we add that amount for the weapon”, and simplify that to “we have this base dam for an attack; we add this amount for the weapon if thrust and that amount if swung”. In the end, we move the extra swing damage that RAW ascribes to ST (let’s call it “ST swing bonus”) away from ST, and into the weapon’s swing damage add (where it arguably belongs).

Weapon damage adds become your one-stop shop for thrust-vs-swing differences. The need for two ST-based damage scores goes away.

“How would you set ST-based damage and weapon damage adds to begin with?”

It could be done however you like. Here’s the outline of a way that favors RAW-like results:

First, we give all characters a single ST-based damage score that forms the base for all muscle-based maulings, whether punch, bite, knife stab, axe swing, whatever. It’s not inherently a thrust, a swing, or anything else specific, so let’s give it the generic name “strike” or “stk”.

How much damage is stk? We could set it to whatever we like, and then set weapons’ damage mods accordingly, to get the desired final numbers. But let’s keep this dead simple here, and just steal RAW thr damage scores to use as stk: 1d-2 for ST 10, 1d for ST 14, and all that.

Next, how do we set weapon damage adds? For a punch, stab, or other thrust-type action, let’s again keep things simple by stealing thr damage adds from GURPS tables. This gives us stk-1 cr for a punch, stk+3 imp for a thrown spear, and so on.

And swung weapons? Once more, let’s stay simple by taking existing swing damage adds from the tables: if the table lists a weapon as “sw+2”, we start with “stk+2”. But we also need to fold ST swing bonus (a swing’s extra ST-based damage) into this. So we’ll just take the extra damage awarded by a swing from the Damage Table (Basic Set p. 16) – but wait, the extra damage for what ST? Do we set this to the difference between swing and thrust damage at ST 10? Or ST 12? 15? 63?

Let’s go for a ST swing bonus that’s appropriate to the weapon. The easy way to do this: Nab the ST swing bonus for the weapon’s ST stat – the weapon’s Min ST, as it’s often called. For low ST, you can just eyeball the obvious point difference (e.g., 2 points for thr 1d-1 vs sw 1d+1 at ST 11). For higher ST scores, take the difference in average damage, rounding up. It works out like this:

  • Min ST 9 or less: ST swing bonus = 1
  • Min ST 10 to 11: ST swing bonus = 2
  • Min ST 12 to 13: ST swing bonus = 3
  • Min ST 14 to 15: ST swing bonus = 4
  • Min ST 16 to 18: ST swing bonus = 5

And so on. (Actually, we have an oddity here: the ST swing bonus for Min ST 16 to 18 dips down from 5 to 4 at ST 17, as the Damage Table is a thing of mystery. As I’ve done here, smooth over any bumps like that.)

So, for that Min ST 10 broadsword, instead of RAW thr+2 imp and sw+1 cut damage, we have stk+2 imp (with a thrust) and stk+3 cut (with a swing, computed as sw+1 from the weapon table plus 2 for the ST swing bonus). Wielded by a ST 10 PC with stk damage of 1d-2, the result is 1d imp or 1d+1 cut – the same as RAW, but arriving by a different path.

“But wait… doesn’t this do away with a swing bonus that varies with character ST?” 

Yes! With this idea, the thrust-vs-swing difference for a given weapon is static, meaning that the above broadsword deals 1 more basic hit with a swing than with a thrust regardless of who uses it.

Er, is that something we want? For our ST 10 PC, the results are the same as RAW, which is presumably a good thing. But what about a ST 24 (thr 2d+1, sw 4d+2) ogre warrior? GURPS would have this bruiser deliver thr 2d+3 or sw 4d+3 damage with a broadsword, nabbing a bonus of two dice damage for swinging, not 1 point! Isn’t something wrong?

I don’t think so. I rather like this! That is, I’m happy with the ogre picking up lots of extra damage by using a swing – with an appropriately big weapon, that is. If he just swings a puny human broadsword… well, a puny 1-point damage bonus is arguably sensible. A broadsword to this ogre is like a knife to a human. The big lug arguably shouldn’t gain a massive damage bonus from swinging the little thing.

“I dunno about this. More examples!”

Looking at Min ST 10 weapons, we get stk+1 imp (thrust) stk+2 cut (swing) for an edged rapier, and stk-2 imp (thrust) stk+3 cut (swing) for a falchion.

How about a mace? Take the weapon table’s sw+3 cr and add the ST swing bonus of 3 for Min ST 12 to get stk+6 cr damage for a swing.

A halberd? Let’s see: a thrust attack uses the +3 from thr+3 on the table. For swings, take the weapon table’s sw+4 imp and sw+5 cut, and add the ST swing bonus of 3 for Min ST 13. Final stats: stk+3 imp (thrust), stk+7 imp (swing), stk+8 cut (swing).

How about a humongous club? Take the weapon table’s sw+6 cr and add the ST swing bonus of 5 for Min ST 16 to get a club that delivers a delightful stk+11 cr damage with a swing!

Let’s go in the other direction and look at a wee short baton. For thrusts, there’s no damage add on the weapon table, so we use straight stk cr. For swings, we take the weapon table’s sw-1 cr and add the ST swing bonus of 1 for Min ST 5. Final stats: stk cr (thrust), stk cr (swing).

Whether you’re halfling or human or ogre, swinging this little stick yields no more basic hits than does a thrust. This is good, IMO! It meshes perfectly with RAW’s assumption that small objects in hand have no appreciable swing damage score.

“For big swung weapons, some of those damage adds look crazy high. Are you sure about those?”

Yep. By design, the above mace’s stk+6 damage yields the same damage as RAW when used with ST 12. The humongous club’s nutty stk+11 yields the same damage as RAW when swung with ST 16. (Actually, it ends up 0.5 points higher, thanks to rounding. I’m good with that!) It’s all fine.

Those big-looking damage adds are, by design, less generous than RAW when wielder ST rises beyond weapon Min ST. With humongous club in meaty hand, our ST 24 (stk 2d+1) ogre delivers stk+11 damage, which means 2d+12 or average 19 damage. That’s a lot, but RAW would have him deliver 4d+2 ST-based sw damage, +6 for the club’s sw+6, or average 22 damage. I’m fine with this loss of a few points of damage. The humongous club is much more appropriate for the ogre than a broadsword, but at Min ST 16, it’s still rather akin to a little Min ST 8 knobbed club or smaller in the hands of a human. To get the full effect of his power, this poor ogre should demand a proper Min ST 24 über club!

“Wait… isn’t stk+11 damage far too generous for my wee halfling thief?”

It certainly would be if he could use the club, but he really can’t. RAW penalizes his use of the weapon for not meeting Min ST.

Actually, RAW only applies TH and fatigue penalties, so technically, the halfling can use this club at full force. That feels odd, whether you’re playing with this article’s change or playing pure RAW.

I think GURPS needs to also apply a damage penalty for using a too-big weapon. I’d create some penalty for failing to meet Min ST (halve the weapon’s damage adds?), or use something like “a weapon’s damage add may not exceed the wielder’s STx2/3”.

Whatever the details, we can take steps to ensure that a little character’s blows with a humongous club will be both clumsy and appropriately weak.

“Shouldn’t a weapon’s swing damage add really be figured from its weight, length, balance, stuff like that?”

It should and could, if you use some sort of weapon design system to generate stats. But even without that, the swing damage adds generated above do figure in those factors, if roughly. They’re built from GURPS‘ weapon table damage adds and Min ST scores, which presumably incorporate those factors (by feel if nothing else).

“Any other considerations worth noting?”

I’ll note that reworking swung weapon damage adds as above isn’t particularly fun, but keep in mind that the idea calls for a one-time revamp of weapon tables. None of that would go on in the game!

That said, reworking swung weapon damage adds isn’t particularly difficult, either. Change “sw” in any weapon stat to “stk” (or “thr” if you prefer; we’re setting stk equal to thr anyway). Boost the weapon’s sw damage add by an amount based on its Min ST, as noted above (+2 for Min ST 10, +3 for Min ST 12, etc.). That’s it.

There’s a bigger consideration. When some trait or circumstance boosts striking power, RAW typically grants a greater bonus to strikes that use swing damage. For example, the trait Weapon Master yields damage bonuses based on dice of ST-based damage; in play, that often results in swing gaining twice the bonus that thrusts enjoy. Similarly with the Power Blow skill: it evokes the image of a powered-up punch, but a character who uses it with a swung weapon gains a lot more damage.

For better or worse, this article’s idea would hand a character with Weapon Master or Power Blow the same extra damage whether using a thrust or swung weapon. (Which again is a small simplification.)

Swing for the fences?

Along those lines, if you were actually going to implement this idea, it’d be a good opportunity to go wild and really rethink a lot of things from the ground up:

  • You could rework stk as you like, perhaps giving it a neat linear relationship with ST.
  • You could ask yourself whether the under-the-hood ST swing bonus should then follow some neat relationship with base stk damage. (Along with this side topic: Shouldn’t Lifting ST, not Striking ST, aid in meeting weapons’ Min ST? Yes, it should.)
  • You could consider a weapon design system to systematically generate weapon damage adds for thrusts and for swings.
  • You could really go nuts and rethink the whole idea of weapon damage adds, perhaps implementing them not as mods to damage itself but as mods to effective ST for the purpose of looking up damage: +4 effective ST for thrusts instead of +2 thr dam, +6 effective ST for thrusts instead of +3 thr dam, etc. The obvious benefit would be finer-grained weapon damage: a sword that adds +5 effective ST for thrusts falls neatly between those two examples (essentially “+2.5 thr dam”).

All among many other “let’s build the perfect combat system” schemes that come to mind. But such things are outside the scope of this article.

“So. You think this change would be a good idea?”

Well, it has some advantages:

  • The idea simplifies both the Damage Table and character sheets, as ST-based swing damage scores become unneeded. Extra damage for a swing is built entirely into the weapon (and is appropriate to the weapon).
  • Simplification aside, building the swing damage bonus into the thing that gets swung, not into the character, just makes sense to me.
  • Building swing damage bonus into the weapon reins in the super-high swing damage scores that result from RAW when mighty characters wield little weapons. Even more than under RAW, mighty characters will want appropriately big swung weapons to take full advantage of their strength. (A task I see as best aided by Lifting ST, not Striking ST, but that’s its own topic.)
  • The idea results in identical damage bonuses for thrust and swung weapons when a character uses power-boosting traits like Weapon Master, Power Blow, or DFRPG‘s Expert Backstabbing, rather than favoring swung attacks with greater bonuses. Whether that’s overall a good or bad thing, it does provide another small simplification.
  • Why, on GURPS‘ Damage Table, does swing damage max out at an odd 2d over thrust damage, instead of always following some multiple of thrust? (I suspect it was initially set up that way to stop giants and supers from multiplying their already-massive damage just by swinging a baton.) What’s the ideal ratio of ST-based swing to thrust damage? By throwing away ST-based swing damage scores, we can throw away questions like these too.

But. Under-the-hood niceties aside, in play we’re talking a few points of difference in damage here and there, with minor simplification to tables, character sheets, and some damage calculations. It’s nothing that’ll imbue your adventures with magic and take your game to new heights of awesomeness. Moreover, the above is a rough sketch, in need of refinement and more testing.

Just tossing out the basic idea, for those who have asked. Should you tinker with it, leave a comment here and tell the world what you came up with!

Header image: I have no image that illustrates the topic of this article, so enjoy this in-Seine view of knights battling over a famed river in France. Or maybe it’s engineers, fighting over who made this tiny bridge too short.



    Building the extra oomph you get from swinging a weapon into the stats of the weapon does make more sense than building it into the character. The mechanical advantage you get from swinging a hurtystick (as opposed to thrusting that same hurtystick) depends on the physical properties of the hurtystick, not on the force with which you can swing it. But your example with the ogre conflates strength with size. The ogre gets less mechanical advantage out of swinging the sword because it’s small relative to him. If you compare two SM+0 humans with different ST levels swinging the same sword, you’ll see a difference.

    In my own Ideal Combat System, I would have swing attacks work exactly as their description on B15 suggests and replace the swing damage add with a swing damage multiplier. Then, to solve the issue with the ogre, I would reduce this multiplier for characters trying to use weapons inappropriately sized for their SM.

    • tbone

      I don’t think I’m conflating the ogre’s strength with size; or at least, not unintentionally. By which I simply mean: I’m considering wielder ST alone here, and am not considering size at all. If you replaced my example of “ST 24 ogre” with “ST 24 human”, nothing would change – and that’s by intent.

      Now, should difference in wielder size (arm length and all that) also affect things, including the thrust vs swing damage differential? Most probably. But GURPS doesn’t consider that, and I’m not considering it here either. Some other time, in a more detailed system. For here and now, just one complication at a time. : )

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.