Katie Sandwina

Game design musing: Notes on ST in GURPS

GURPS has a long history of wrangling the cost and workings of ST to make it behave. Simultaneously the most straightforward and the most wily of attributes, ST commands a bizarre amount of attention on this very site.

While writing up STROLL, I found myself with a bunch of longer takes and miscellaneous notes on ST-related topics that didn’t quite belong in that article. Well, waste not, want not, Grandma Bone (allegedly) said, so here’s the content for the few interested souls out there.

I’ll probably add other stray thoughts on ST to this page in the future. (Maybe rants like “Grrr, lazy media articles, quit saying ‘insects are so super-strong’. No, they’re not.“)

Anyway. Don’t spend too much time reading this sort of stuff, okay? You’ll go weird. (Too late, you say? Well, that explains why you’re here…)

The problems with ST rolls, redux

In STROLL, I replaced a too-wordy text recap of what’s problematic about ST-related rolls with something shorter. Here’s the long initial version, for the undiscerning reader. Skip ahead if this is old, obvious stuff for you!

You’ve probably seen oddities crop up in Contests that pit ST against HT or other attributes, in skills based on ST, and even in straight rolls versus ST that are written for – and really only work for – “normal human” levels of ST. I refer to the hapless trials of a ST 2 pixie PC who’s barred by rules from strangling even a tiny mouse-sized foe, or providing a “leg up” to assist even a mouse-sized pal’s climb. “Nope, can’t do those things”, the rules obstinately insist.

Maybe a more subtle problem is how differences in ST interact with dice rolls, especially in Contests of ST. In GURPS‘ Contest mechanism, absolute differences in scores determine margin of victory. That’s arguably fine for abstract attributes, skills, and so on; if the difference between Skill-6 and Skill-5 is conceptually the same as the difference between Skill-26 and Skill-25, then it’s fine that the game handles the respective Quick Contests as essentially the same thing.

But the ST attribute is uniquely associated with decidedly non-abstract properties, particularly lifting/carrying power. In a Quick Contest of ST 2 vs ST 1, one contestant boasts quadruple the lifting power of the other, while in a Quick Contest of ST 102 vs ST 101, the relative difference in physical power is negligible. Yet because the absolute difference in ST is the same for both Contests, the Quick Contest mechanism treats both Contests as equivalent, with the same likelihoods of outcomes.

In Regular Contests of ST, absolute ST scores can easily be too high or too low to accommodate meaningful rolls, necessitating the “Extreme Scores” fix. That patch does seek to preserve the relative difference in ST through the mechanism of “reduce the lower score to 10 and multiply the higher score by (10/lower score)”, a workable method even if it isn’t exactly lovely in play. But it also means that Regular Contests and Quick Contests end up taking two different paths in how they treat differences in ST. (And the above multiplicative fix should also be used to fix Contests of low ST scores, not just high scores.)

Then there’s the bigger problem: rolls against ST that don’t properly consider target difficulty. Take the leg up (a roll against ST) and pull-up (a roll against ST-based Climbing) feats that pop up on Action 2: Exploits p. 19 and elsewhere. It’s fun stuff, but the feats automatically pit ST against normal human body weights, not the actual weight involved. The backward-seeming result: fantasy pixie PCs fail miserably at pull-ups while huge giants yoink themselves up ease.

STROLL doesn’t fix this category of rolls; the workings are fundamentally flawed. When target difficulty should reasonably vary, rolls against ST need to account for that if they’re to yield good results. Mark the words of GURPS Line Editor Kromm, from “Knowing Your Own Strength” in Pyramid 3/83: “The Basic Set allows for the possibility of ST rolls, but they don’t make much sense except when they’re opposed by other ST rolls in a Contest.”

I agree. For nearly all problematic rolls against ST, the universal fix is simple in concept: replace ST with ST Roll so relative differences in power have the right effect, and – most importantly – pit that ST Roll against proper target difficulty. In a Contest, that’ll often mean an opposing ST Roll. In non-Contest feats of ST, it’ll typically mean some modifier based on the weight or other resistance to be overcome, such as an appropriately big bonus when applying a leg up to a tiny critter’s weight. (Pixie PCs will thank you for gaming things that way.)

Getting faux-philosophical: Just what is a roll against ST?

Ah, the roll against ST. Such a simple thing, yet it leads one to wonder: Why do we handle some solo feats of strength (like bending a steel bar) with rolls, while handling others (like lifting a given weight) statically, without rolls? Just what does “roll against ST” even mean?

A thoughtful answer to this question is… non-essential, wordy, and (for most people) dull. Here it is anyway:

When it’s time to carry, lift, or shift a heavy weight, GURPS uses static resolution: you either do or don’t have the Basic Lift needed. Similarly, the game statically specifies that ST 10 or higher can wield a broadsword properly, while ST 9 and lower will struggle, and that’s that. The rules offer no rolls against ST to perform these feats of power (let alone some even more complex Contest using a roll against ST and a roll against some trait representing the weight to be moved).

Yet when it’s time for a PC tough guy to bend the bars of a jail cell, we generally don’t follow that same method to rule “you need ST 15 to bend the bars” or “you need Basic Lift of 45 lbs. to bend the bars”. Instead, we bring in randomness with “make a roll against ST”. It’s as if a PC’s physical power is a fixed quantity where most physical feats are concerned, but it suddenly becomes a variable entity when faced with other tasks, like bending bars. Why?

I don’t know what the designers would say, but my take is this: Such a roll against ST represents an intentional decision to leave the target physical power required for the task undecided, pending a roll. This could be done by literally rolling the required power: “Roll 3d+5 for the ST of the window bar; a character with ST greater than that can bend it.” Instead of that, though, we roll against the PC’s ST and implicitly use the roll’s success or failure to interpret the resistance of the target: “Looks like the bars were weaker than you!” or “Uh oh, looks like the bars were stronger than you after all.” Restated: although we roll against the PC’s ST and call it a test of the PC’s physical power, in a roundabout way we’re really testing the bars‘ strength in terms of their indeterminate ability to resist the PC’s fixed physical power.

So we treat the weight of a backpack as a known quantity because it is known (or easily knowable), and because rolling dice to “test” lugging it would be weird. But we treat a metal bar’s resistance to bending as an unknown because it reasonably would be unknown, and because a roll for such a feat is a traditional and fun bit of gaming.

That’s my take, anyway. (My apologies if you were expecting something insightful.)

Arm wrestling and Contests of ST

Jumping off from that, let’s look at a classic competition of strength: arm wrestling. Here there are no metal bars of unknown strength, just characters of known physical power. And since that power doesn’t reasonably bounce around the way dice rolls do, an arm wrestling Contest of ST technically should involve a static comparison of ST in which victory automatically goes to the higher ST, all else being equal.

But that’s not much fun. First, all else isn’t equal: technique matters, as does “grit”, so we maybe add mods for skill and for extra effort. (These are both abstract elements, so could reasonably involve dice rolls.) The result – two opposing ST scores, each modified appropriately for technique and effort, with victory automatically going to the higher total – would be a perfectly good model for the bout. But most players want yet more randomness. So instead of such a static comparison of modified ST, we use a roll-based Contest of modified ST, because even more randomness in a contested situation is considered fun, and it’s the gaming way to do things. It’s all good.

The Quick and the Regular: which Contest to use?

The above raises a side topic: when should opposed tests involving strength – and even those not involving ST – use Regular Contests and when should they use Quick Contests? Some old thoughts on the matter:

Basic Set p. 348 uses an arm wrestling match to illustrate a Regular Contest, and two fighters lunging for a fallen gun as an example of a Quick Contest. In both examples, the Contests deliver the goods in the end, so all is well. Yet you could switch Regular and Quick Contests for these two opposed feats – and depending on how you want to model the feats, you might even prefer a switch.

Quick, not Regular, Contests for arm wrestling?

What’s wrong with a Regular Contest for arm wrestling? Well, it unfortunately calls for the “Extreme Scores” fix when neither ST score is close to 10. And once that fix is applied to scores, the Contest will probably end pretty quickly. That isn’t necessarily bad, but it does mean you’re not likely to get an epic, dragged-out battle, even when power is evenly matched. Also, while Basic Set describes the action as having “much give and take”, that isn’t actually represented in the results. Until the battle ends, contestants start every new turn on the same unchanged footing as the first turn, neither side having moved closer to victory.

Digging deeper, a Regular Contest arguably just isn’t right as the underlying model. Each contestant’s roll in a Regular Contest is a success roll, meaning a pass-or-fail roll to succeed at some task. Arm wrestling, though, is a matter of exerting strength – and neither contestant can fail to do this! Exerting some degree of strength is naturally successful. The only question is how well each contestant did so.

All in all, this is arguably a perfect situation for a Quick Contest. A Quick Contest directly tackles “how well”, not “pass or fail”, through margin of success and margin of failure. It yields a logical result whether both parties rolled under ST, only one rolled under ST, or both rolled higher than ST. (In references to rolls here and below, read “ST” as “ST Roll” if you’re using STROLL.)

Not so quick!

Note that that “quick” doesn’t have to mean the struggle ends in a second, any more than two generals’ Quick Contest of Strategy is a one-second affair. In a test of physical power, a strong margin of victory would logically mean a fast conclusion; a weak margin of victory, a protracted battle. You can leave the exact time unknown, if you like. Or if you want resolution that follows turn-by-turn combat time, there are creative ways to get that in a Quick Contest. For arm wrestling, you get exciting matches by letting turn-by-turn margin of victory accumulate, until one side racks up a cumulative advantage of (say) 10 over the rival. An overwhelming advantage in ST could end the match in one turn. A small advantage in ST will likely conquer the rival, but require several turns to do so. With closely matched ST scores, meanwhile, a bout might see-saw for quite some time – not by way of colorful description, but as actual swings of current advantage between the contestants.

The above can be applied to other feats of strength. Wresting a grappled weapon from a foe is presented in rules as a straight-up Regular Contest of ST, but a Quick Contest also works: ST vs ST, with accumulated margin of victory ending things. Here, something more quickly decisive than arm wrestling sounds right to me: say, an accumulated margin of victory of 3, not 10. A struggle of closely-matched strengths may still see-saw for some time, though not as long as the above arm-wrestling match.

In the end, struggles like these are arguably better suited to Quick Contests than to Regular Contests, and with no need for “Extreme Scores” fixing.

Regular, not Quick, Contests for gun-grabbing?

While we’re at it, Contests that don’t involve ST might also enjoy a switch-up in mechanism. Like those two fighters lunging for a fallen gun: Basic Set uses this as an example of a Quick Contest, but in turn-by-turn gaming, I’ll suggest a Regular Contest as a sensible model. Trying to quickly grab an object is a classic succeed-or-fail test, the domain of success rolls. On any second of the Regular Contest, one fighter might succeed on the DX roll and grab the pistol while the other fails, ending things with a quick and clear outcome. Or both might make their DX rolls and grab at the right spot (with the GM ruling that the higher margin of success gets there first). Or… both fighters might fail their DX rolls and grab at air, in which case neither seizes the gun and the scrabble continues for another turn.

I think this turn-by-turn Regular Contest is a perfect model for this struggle – and as it’s not a ST-based Contest, there’s no need for an “Extreme Scores” fix at any level. (Using scores as-is means that a Regular Contest between two low-DX gun grabbers might run amusingly long, and logically so.)

So… Regular or Quick?

I had long thought that Basic Set got things a bit backward in suggesting a Regular Contest for arm wrestling and a Quick Contest for that gun grab. But while I like the swaps I present above, Basic Set isn’t doing things wrong.

For all the issues presented above, a Regular Contest does work for arm wrestling! Victory for the stronger side is likely but not a given, which of course is good, and things even get exciting when the rolling unexpectedly stretches past a few turns. And if you’re not concerned with second-by-second in-game combat time, fast real-time resolution is a good thing. You can wrap up the Contest at the table with one or a few opposed tosses of the dice – and if you like, go ahead and call it an epic four-minute bout in game time, with (imagined) wild swings in position along the way.

Similarly, while I think a turn-by-turn Regular Contest is perfect for that gun grab, a Quick Contest is fine for a struggle on an abstract time scale, when it’s obvious that someone will eventually get the gun and we’re not concerned with how long it takes. A Quick Contest provides a clear-cut result with just one set of rolls, and that may be exactly what you want.

The point of all the above? It’s this bland conclusion: For a lot of contested feats, you can likely go with a Regular Contest or a Quick Contest. I generally prefer Regular Contests for cases of true succeed-fail actions and Quick Contests for cases of continuous exertion (like most ST-related actions), but often you can mold either Contest to fit the purpose. It comes down to how you want to model the action in question and what outcomes you want as a result. So for any Contest at hand, keep both options handy at the top of your GM toolbox.

Yo, ST, do you even attribute?

Getting back to all things ST, here’s an evergreen topic:

ST differs from its fellow attributes in several ways. Many people have discussed this on this site, on other sites, in forums, and of course at gaming tables.

I’ll start a list of how ST differs from its compadres:

  • ST has no “natural” bounds, like the range of 1 to 20 that’s “normal” for attributes (which, with exceptions, tend toward values of 8 to 15 or so). There’s no universally “normal” range for ST; what’s normal naturally varies by creature (with a strong connection to SM), and can be all over the map.
  • The ST score itself has little use in game action. ST lives mainly as a pointer to other calculated or looked-up stats that are actually used in play: damage scores, Basic Lift, and BL-related values like encumbrance levels. (True, ST is used for a number of rolls in play – but done properly, those usually call for fixes of the “Extreme Scores” variety, or replacement of the ST score with the looked-up ST Roll score, or other massaging of the situation, further leaving the raw ST score bereft of direct use in table action.)
  • ST’s tie to measurable physical power, and its interaction with real-world measures like weight, give it a non-abstract character not found in other attributes. This in turn gives special significance to the matter of relative versus absolute differences in ST.
  • For reasons including those noted above, ST can create problems when used as a base for skills. 4e mainly avoids doing so, although it calls for ST-based skill rolls here and there. (These aren’t necessarily bad, if handled right!)
  • ST has entertained all sorts of oddball pricing schemes in the past. Cost is kept pretty simple under 4e, though with a SM-related adjustment that has no counterpart in other attributes’ costs.
  • More than other attributes, ST still invites variant schemes – not “what if” minor tweaks of the sort that pack Power-Ups 9: Alternate Attributes, but fundamental alternate approaches to ST including those worked out and presented in Powers, Supers, and “Knowing Your Own Strength” (Pyramid 3/83).
  • Fractional scores would have very little meaning for most attributes; the scores would quickly get rounded to integers for nearly every use. But ST? Fractional scores are workable from the get-go, with associated values like Basic Lift and ST Roll figured in the normal way. What’s more, fractional ST scores are arguably needed to model small creatures properly!

That’s a quick take, anyway. What else belongs there?

Header image: Early 20th-century performer Katie “The Strongest Woman in the World” Sandwina. Horseshoe-straightening, cannonball-juggling, husband-lifting… all in a day’s work for Katie.


  • fellrant

    Many years ago, I ran a homebrew supers game where strength was handled completely differently from everything else. The game was primarily skill-based, lacking a traditional attribute set entirely. And strength was really chonky; the entire human ability range was 1 point, with each successive point multiplying your lifting capacity by x8. The Lifting skill provided for more fine-grained results, but damage was just a fat boy sandwich. It played quite well for the Justice League-esque party I ran it for; the masked vigilante had no trouble operating alongside our flying brick, who could canonically juggle elephants. But yeah, strength rolls weren’t a thing; the rules literally made no provision for it, because it was just so obviously bonkers.

    • tbone

      Man, and here I thought the old DC Heroes RPG was radical with its (IIRC) “+1 ST = x2 power” scaling. The game you describe is, as you put it, “bonkers” indeed. : )

      And probably fun! Running with unusual ideas can inspire new insights into what is or isn’t needed, or is or isn’t fun. Dropping concepts we take for granted – like meaningful ST differences within the human range – can free up players to explore other approaches to game play. Even in things as trivial as game rules, we should all step out of our comfort zone like that, more often…

  • Charles Saeger

    Would something like opposed thrust damage rolls work as a contest? (Ignoring swing; that should be thrust+2 per die anyways.) Or have thrust damage as its own attribute at 40 points per die, and having BL and HP somehow vary as well.

    • tbone

      Interesting timing on your comment. Literally 5 minutes before a notice of your comment popped up, I had just completed a down-the-rabbit-hole deep dive of every page on your site (which anyone seeing this comment should go visit now: http://gurpshexytime.blogspot.com ). I was bookmarking useful resources, taking notes on ideas I want to put into play, scrapbooking bits I’ll probably link to in future posts… I unfortunately didn’t have time to read through the game plays (a monumental body of work right there), but all the hexcrawl how-tos, armor loadouts, skill/disad commentaries, etc. are really great stuff.

      Anyway. Re opposed dam rolls: You mean rolling and comparing dam rolls as a stand-in for Contests of ST? Yeah, it’s a way to do things. I think it’s been sitting there from the start of GURPS as a potential way to game opposed actions, but didn’t get any attention until more recent times. Technical Grappling’s Control Points work along those lines, and I believe “Knowing Your Own Strength” suggests opposed dam rolls to mimic Contests of ST…

      So, it’s a thing, and as you suggest, it could probably be used a lot more. My only reservations for using it myself are:
      1) using dam rolls, especially thrust, the compared values are much grainier than if using ST, and particularly wonky at very low ST; and
      2) variance is so dependent on degree of damage. Down in the damage range of 1d±n, outcomes have such a different variance from the beloved 3d bell curve.

      None of which precludes use, of course. As it happens, with ST Roll in hand, I already have a solution that I like for Contests of ST, but opposed dam rolls remains an interesting alternate way to do Contests of ST, or a mechanism that could be applied to other ST-related effects (cf. Control Points).

      Or even applied to non-ST effects. I don’t know whether any niche corner of GURPS has explored that idea: take the Damage Table, read “damage” for DX, IQ, a skill, etc., and apply that “damage” to some Contest or progressive task. Will- or Exorcism-based “damage” to battle an evil spirit? Interrogation-based “damage” that lessens a target’s Will? A comparison of Tactics-based “damage” to see which side outmaneuvers the other?

      I don’t know, I haven’t explored this area. Maybe it’s all unneeded, as for any skill or attribute (except ST), the usual business of margin of success/failure on a roll and the usual Contest mechanisms work fine. Still, maybe someone could come up with novel and fun uses for “damage” scores. Give that Damage Table more of a workout!

      Side note re “Ignoring swing; that should be thrust+2 per die anyways”: Yes, I agree with the general principle, and think it’s a good simplification to the rules – though I strongly prefer replacing that “+2” bonus with a more variable one that reflects weapon size. Details for the interested: https://www.gamesdiner.com/2022/01/game-design-musing-simplifying-st-based-thrust-and-swing-damage/

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