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.

So. A PC with ST 10 delivers a base 1d-2 damage with a thrust attack, and a base 1d damage with a swung attack. She wields a broadsword, which deals thr+2 imp or sw+1 cut damage. Her damage with the sword becomes thr 1d imp and sw 1d+1 cut.

Per rules as written (RAW), we can consider this PC as having two inherent ST-based damage scores (thr 1d-2 and sw 1d), modified by a respective thr+2 and sw+1 for the sword, yielding 1d imp damage with a thrust and 1d+1 cut damage with a swing.

Or, bidding fond adieu to RAW, we could consider the PC as having one inherent ST-based damage score, modified by a reworked +X and +Y for the sword, so that the totals again yield 1d imp damage with a thrust and 1d+1 cut damage with a swing.

That’s all.

“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?”

Right. Instead of the RAW practice of breaking up a swing’s damage bonus into a part that’s innate to character ST and a part that’s innate to the weapon, we’d set a nice ST-based damage score for thrusts (just like RAW), and we’d set thrust and swing damage mods for weapons (just like RAW) – but we’d also take the extra swing damage that RAW ascribes to ST (let’s call it “ST swing bonus”), and move that 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?”

I have no “This Is the Way” system. Here’s a skeleton of one way to work things:

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. Since it’s not inherently a thrust, a swing, or anything else specific, let’s give it the generic name “strike” or “stk”.

How much damage is stk? Let’s keep this dead simple here, and just steal RAW thr damage scores: 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. But we also need to also fold ST swing bonus (the extra ST-based damage from a swing) into this. We can easily get that from the Damage Table (Basic Set p. 16) – but 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 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 know. 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 actually 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, 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!

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

Well, it 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. 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 that 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!

As small and simple as the idea is, implementing it would of course affect other bits of the game system and require attention. For example, the trait Weapon Master yields damage bonuses based on dice of ST-based damage; this idea obviously mucks that up for swings. You’d probably want to rework how Weapon Master sets its damage bonuses, perhaps basing them on ST itself instead of on dice or points of damage. Then there’s this point: As your striking power rises beyond your weapon’s Min ST, your damage with a swing will rise only as fast as thr damage rises (assuming you’ve set stk equal to thr), a progression slower than RAW. This might suggest lowering the cost of Striking ST.

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. You could even consider a weapon design system to systematically generate weapon damage adds for thrusts and for swings. All among many other “let’s build the perfect combat system” schemes that come to mind.

But that’s far beyond this article.

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

Well, I think 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 weapon, 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 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.)
  • 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 picking up another 5d 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 a very minor bit of simplification in tables and character sheets. It’s nothing that’ll imbue your adventures with magic and take your game to new heights of awesomeness. Moreover, the above is just a rough sketch, in need of refinement and 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 the bridge too short.

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