More on ST Rolls: Me agreeing a lot with Peter

+Peter V. Dell’Orto made a very on-point comment about my post Go ahead and roll vs. ST. Worth responding to in detail, so I did. His words are in blue-italics, mine in indented black.


I understand the impulse here, and I respect the work you’ve done, but:


– it’s got to be simple.
– it’s got to be a roll, because we don’t just say “DX 14? You just make it.”
– it’s not good if the roll makes another attribute into ST in order to avoid using ST (i.e. HT-based rolls to avoid ST-based rolls)

I tried, and perhaps failed, to make that clear in my Parting Shot. Well, parting fusillade, since I had an entire section there. But yeah, it does have to be simple. Some of the “don’t bother rolling” is to avoid ridiculous edge cases such as when someone pointed out that it was theoretically possible for someone of normal-human size and strength to fail to do a Pickup on a mouse.  

That was an artifact of the scaling at fractional multiples of Basic Lift getting quite crazy. PK and I deliberately stopped it at the low end, but didn’t put the line in saying “just don’t roll if you’ve got a ST 10 guy picking up a 2-lb object.”

I agree that all opposed contests should involve a roll. That’s why I pegged the expectation of automatic success at 14 to 16. 16 is convenient because it still allows for a crit fail.

This is why I still have rolls vs. ST, and why I’ll cheerfully normalize around ST 10 like in a Regular Contest of ST. Is it perfect? Not really. Can it be recursive? Yes, but so can any roll (I roll against DX to see how agile I am!). Is it simpler to use a stat on the sheet and not look stuff up? Yes. Done and Done.

Rolls vs. ST that are normalized vs a foe aren’t too bad, I suppose. I don’t like them, but they get the right approach. Rolling vs ST for things like Wrench Limb or to pick up a rock are problematic (the second much more than the first) because of the extrinsic nature of it.

The most useful part of my post, I think, is really the “this is how you can calculate an extrinsic penalty to make the ST roll vs an inanimate object not stupid.”

This is why everyone knows that you can jump over at hex at cost 2, but has to look up their Broad Jump. One you look at, one you look up.


I’d be fine with a replacement, but it’s got to be vastly better if it’s going to be even a little more complex and/or slower to use in play.

Well, I agree. That’s why the opening line of my Parting Shot was “well, this sucks.” Because even though “roll vs ST” has issues, “roll vs HT, then a complicated ST calculation, and if you fail that roll DX, and if you fail THAT roll HT again” is simply awful. It would work as a computer macro (and be pretty damn satisfying, at that). It would not work at the table, for the same reasons – it requires a computer even when things go well (to figure the Weight Penalty of an object and the corresponding Injury Modifier based on lift speed).

 TG has the beauty of swapping a single system that’s simple and binary with a single system that is simple and not-binary. That’s the standard I like – does this make my life easier and give better results? Perfect! One of those two? Okay. Makes things more complex and/or gives worse results? No.


This can be an impossible task with ST, being that it wasn’t designed ground-up to do all the things it could do.

This was the core of my findings. ST being extrinsic and not-simple (quadratic in nature) to calculate using the standard GURPS resort for such things (SSR table) means that anything you want to do requires breaking out the calculator (what’s the ST equivalent for a 1,356-lb rock? Gah! 82.3. That’s not helpful).  

Even switching to cubic ST, which I explored in a prior post, doesn’t help. It just switches the basis from a square root to a cube root. Booyah? No, that’s no better, and in fact it’s worse. 

Logarithmic ST based on the SSR would be better from that perspective, since it’s either a table lookup or something that many (not all) have internalized. Double the SSR value as a penalty has worked well enough in TG in the Grappling Encumbrance Modifier Table. That would pretty drastically reduce the resolution of ST though. 

As you note, I don’t see an easy answer there that meets our criteria – fast, realistic, easily playable. 

But I’m going to keep looking.