Rethinking SM

[Varyon]

The issue of a lariat's SM recently came up in the Meta-Tech Examples thread, which reminded me of something I've been wanting to write up for a bit - a more precise way of handling SM. Currently, you use an object's largest dimension to set the SM (following the Size and Speed/Range Table), then you add +2 if it approximates a square or circle or +1 if it's an elongated square or circle. The exception is things that have one dimension that is markedly larger than the other two, in which case you set the SM by the second largest dimension.

The first two are arguably fine to eyeball, but that last is a problem. If you have a 1-yard by 1-yard by 1-yard cube, it's SM +0 (1 yard is -2, +2 for being a square). But if you have a 1-yard by 1-yard by 1000-yard square column - what you'd get by stacking 1000 of those SM +0 cubes on top of each other - it is instead SM -2.

What I would like to suggest is something more formal, and which avoids that "really long things are harder to hit" issue, but isn't too difficult to do on the fly. To set SM, you start with the second-largest dimension, checking where it falls within the Size and Speed/Range Table. If the largest dimension is within +1 SSR of the second-largest, use the second-largest at +2. If it's within +3 SSR, use the second-largest at +3, if it's larger than that, use the second-largest at +4. Note this roughly means that a perfect cube uses the largest dimension at +2, anything with one dimension that is up to twice that of the second-largest uses the largest dimension at +1, anything with one dimension that is up to thrice that of the second-largest uses the largest dimension at +0, and anything larger doesn't get any easier to see/target (at least not at GURPS resolutions). Note this is an arbitrary cut-off - you could have it be a further +1 to SM for every doubling (+2 steps on the SSRT) of the largest dimension, but eventually you're going to hit the point where increasing further really doesn't make the target any easier to see/target. I opted to go with +4 compared to the smallest dimension as the cut-off.

Let's consider that cube vs column again. Keeping two dimensions (width and depth) at a constant 1 yard, anything up to 1.5 yards tall is SM +0. Anything up to 3 yards tall is SM +1. Anything taller than 3 yards is SM +2. Or, if you want to continue the progression a bit, anything up to 7 yards tall would be SM +3, up to 15 would be SM +4, up to 30 would be SM +5, etc, at +1 to SM per +1 SSR until you hit whatever cut-off you decide upon.

For GM's who want more precision, a target can have different SM's from different angles of attack; use the two dimensions of the cross-section to determine effective SM. The target's actual overall SM (for estimating weight, determining what - if any - discount the character gets on ST, determining price of a Meta-Tech Device, etc) would be a weighted average of these. For further precision in combat, note that the target's effective SM for targeting them will be no lower than the SM of your weapon's striking surface.

[Anthony]

If you want it based on cross-sectional area, which is pretty reasonable for things like perception, just calculate SM for length, again for width, average, and add 2.

[Varyon]

Originally Posted by Anthony

If you want it based on cross-sectional area, which is pretty reasonable for things like perception, just calculate SM for length, again for width, average, and add 2.

That also works. I feel my method may be a bit quicker, at least for those with SSR already memorized, but there's probably not a huge difference in speed here.

[Tyneras]

I made this chart purely as a personal reference to help me visualize things. It may or may not be helpful since parts of it was just me eyeballing what "seemed" right.

https://imgur.com/a/TBebSqW

[Refplace]

FYI regarding Lariat I added an enhancement to Binding for Lariats, Nets, and Bolas in Template Toolkit 4: Spirits.

[Varyon]

Originally Posted by Tyneras

I made this chart purely as a personal reference to help me visualize things. It may or may not be helpful since parts of it was just me eyeballing what "seemed" right.

https://imgur.com/a/TBebSqW

Note that last one demonstrates the issue with the existing system - if those are 1-yard squares, 1:9 would use the longer dimension at -1, so net SM+3. 1:10 uses the smaller dimension, which would be net SM-2, when it shouldn't be any harder to hit than the smaller 1:9. Replacing that last one with "same as 1:9" should work and give similar results to my suggestion, although yours stretches things at the end out a bit - for both of ours, assuming starting at 1 yard by 1 yard, 1:1 is +0, 1:2 and 1:3 are +1, and 1:4 through 1:7 are +2 in both systems. The difference is that yours (assuming you replace the last part with "same as 1:9") then has things larger than 1:7 at +3, which is the maximum. I like that progression a bit better on account of it not being quite as abrupt of a stop.

Originally Posted by Refplace

FYI regarding Lariat I added an enhancement to Binding for Lariats, Nets, and Bolas in Template Toolkit 4: Spirits.

GURPS Meta-Tech has something similar, the Retractable Enhancement. But it does sound like TT4 adds in a lot of modifiers and the like, so I may want to pick it up even though I'm not that interested in the nominal subject matter.

[Tyneras]

Originally Posted by Varyon

Note that last one demonstrates the issue with the existing system - if those are 1-yard squares, 1:9 would use the longer dimension at -1, so net SM+3. 1:10 uses the smaller dimension, which would be net SM-2, when it shouldn't be any harder to hit than the smaller 1:9. Replacing that last one with "same as 1:9" should work and give similar results to my suggestion, although yours stretches things at the end out a bit - for both of ours, assuming starting at 1 yard by 1 yard, 1:1 is +0, 1:2 and 1:3 are +1, and 1:4 through 1:7 are +2 in both systems. The difference is that yours (assuming you replace the last part with "same as 1:9") then has things larger than 1:7 at +3, which is the maximum. I like that progression a bit better on account of it not being quite as abrupt of a stop.

The chart is intended to be normalized to all the same length and just guestimate how wide something is.

Like a lot of things I do, its a 3 way arbitration between what's mathematically accurate, what's easy to remember, and what looks good.

Since GURPS is human centric, 1:3 1:4 and 1:5 are all roughly in the normal human range, so all get the SM+0 treatment. 1:10 is easy to remember and 1:1 being SM+2 is RAW and 1:2 is pretty boxy, so the other ratios were just slotted in.

[Varyon]

Originally Posted by Tyneras

The chart is intended to be normalized to all the same length and just guestimate how wide something is.

Like a lot of things I do, its a 3 way arbitration between what's mathematically accurate, what's easy to remember, and what looks good.

Since GURPS is human centric, 1:3 1:4 and 1:5 are all roughly in the normal human range, so all get the SM+0 treatment. 1:10 is easy to remember and 1:1 being SM+2 is RAW and 1:2 is pretty boxy, so the other ratios were just slotted in.

Ah, so - roughly speaking - the first entry is a 2-by-2 yard square, the second is 2-by-1, the third is 2-by-0.67, then 2-by-0.5, then 2-by-0.4, then 2-by-0.33, then 2-by-0.29, then 2-by-0.25, then 2-by-0.22, and finally 2-by-0.2. But note, in this case, that loss of ~0.02 yards width (a bit less than an inch) corresponds to going from SM-1 to SM-6. That's one of the things I find unacceptable with the current system, hence my suggestion.
(Also, I just realized that what I thought your progression was actually matches what I had previously suggested, but with a maximum of +5 relative to the smaller dimension rather than +4; I was thinking that my interpretation of yours stretched out the +4 range a bit more, but it did not)

[Tyneras]

Yeah, when I was tinkering with it I was somewhat divided on where to put the dividing line at 1:8 or 1:10. 1:10 won out purely on making it easier for on-the-fly math. 1:8 would make the jump for longest to shortest smaller.

Or one could go with something like this:
1:6 -1
1:7 -2
1:8 -3
1:9 -4
1:10 -5
1:11 Switch to smaller dimension, which would be at -6 for this ratio.

[Refplace]

Originally Posted by Varyon

GURPS Meta-Tech has something similar, the Retractable Enhancement. But it does sound like TT4 adds in a lot of modifiers and the like, so I may want to pick it up even though I'm not that interested in the nominal subject matter.

IF you do let me know what you think.
The Retractable enhancement is good for pulling things but I wanted something that could work like those weapons to match with certain actions. I excluded Retraction as I knew that was going to be put in Meta-Tech.
Also I added options to use Binding more like a spiders web.
There are a lot of modifiers to support various activities, so even if someone is not interested in spirits they should still get solid use out of it.