Helping on skill checks?

[buzz]

Pardon me for asking what's probably a common question, but I am new to GURPS and am not finding this in the FAQs.

How does one or more PCs assisting another on a skill check work in GURPS? I'm not seeing a rule for this in the books.

[Crakkerjakk]

Originally Posted by buzz

Pardon me for asking what's probably a common question, but I am new to GURPS and am not finding this in the FAQs.

How does one or more PCs assisting another on a skill check work in GURPS? I'm not seeing a rule for this in the books.

In stock GURPS, I don't think there are explicit rules.

In Action they introduce a concept where assisting people roll their skills first. How well they roll determines a modifier to the main person making the skill check. Critical failure is a -1, failure is no mod, success is +1, and critical success is +2.

[vierasmarius]

It is a pretty common question, since it's a frequent occurrence in-game yet lacks sufficient explanation in the Basic Set. Per Complementary Skills (Action2 pg5), each assistant make a skill roll (typically without additional modifiers) to add a bonus to the "primary" skill use; Critical Success gives +2, Success +1, Failure -1, and Critical Failure -2. The complementary skills don't have to match the primary one, but can be anything that the GM feels could help complete the task at hand.

Combining ST is handled a little differently. The quick rule-of-thumb is to use full ST for the strongest character, plus 1/5 the combined strength of his helpers. This represents the efficiency loss of a moderately-organized group. If they can coordinate fully and all apply their full strength to the task, add together their Basic Lifts and use that to calculate a new ST score (for example, four ST 10 characters have a combined BL of 80lb, equivalent to ST 20).

EDIT:

Originally Posted by Crakkerjakk

Critical failure is a -1, failure is no mod, success is +1, and critical success is +2.

Check again. Action gives a penalty even for basic failure. =P

[Crakkerjakk]

Originally Posted by vierasmarius

Check again. Action gives a penalty even for basic failure. =P

Ah, my bad.

[Peter Knutsen]

Originally Posted by Crakkerjakk

Ah, my bad.

It has to give such a penalty. Otherwise it's a no-brainer to always try to get a Complemenstary Skill Roll, or an Assist. If the chance of coming out of the process at a loss is microscopic.

[whswhs]

Originally Posted by Crakkerjakk

In Action they introduce a concept where assisting people roll their skills first. How well they roll determines a modifier to the main person making the skill check. Critical failure is a -1, failure is no mod, success is +1, and critical success is +2.

-2, -1, +1, and +2, actually. I had to review it before writing it into Social Engineering.

Bill Stoddard

[whswhs]

Originally Posted by vierasmarius

Combining ST is handled a little differently. The quick rule-of-thumb is to use full ST for the strongest character, plus 1/5 the combined strength of his helpers. This represents the efficiency loss of a moderately-organized group. If they can coordinate fully and all apply their full strength to the task, add together their Basic Lifts and use that to calculate a new ST score (for example, four ST 10 characters have a combined BL of 80lb, equivalent to ST 20).

Actually, I think of those as alternative ways of representing the very same thing. Here are the combined ST scores for multiple people with ST 10 by the two rules:

2 people: 12 vs. 14
3 people: 14 vs. 17
4 people: 16 vs. 20
5 people: 18 vs. 22
6 people: 20 vs. 24
7 people: 22 vs. 26
8 people: 24 vs. 28
9 people: 26 vs. 30
10 people: 28 vs. 32
11 people: 30 vs. 33
12 people: 32 vs. 35
...
16 people: 40 vs. 40
...
20 people: 48 vs. 45

As you can see, there's a long stretch where the two are parallel, and eventually they cross. I think of the 1/5 ST rule as a handy approximation when you don't want to take time out to do arithmetic.

Bill Stoddard

[vierasmarius]

Originally Posted by whswhs

Actually, I think of those as alternative ways of representing the very same thing. Here are the combined ST scores for multiple people with ST 10 by the two rules:

<SNIP>

As you can see, there's a long stretch where the two are parallel, and eventually they cross. I think of the 1/5 ST rule as a handy approximation when you don't want to take time out to do arithmetic.

Bill Stoddard

As I think your chart demonstrates nicely, at the typical group size that will show up in-game (ie, no more than a dozen) the 1/5 ST rule gives effective ST of 10% to 20% lower than combining BLs, or around 20% to 40% lower lifting capacity. I think this is fine for representing a quick lifting attempt that does not optimally utilize everyone's full strength, which fortunately corresponds to situations where you don't want to fuss around with combined BL anyways (ie, when the action is fast and the dice are flying). In fact, I wouldn't use the quicker rules for groups much larger than that, and certainly not at the 20+ member level (where the quick rules provides greater ST than combined BL).

In short, I don't view them as equivalent, but complementary. The mechanical effects provided by the two options are different enough that they merit different usage - one for quick, sub-optimal ST tasks by smaller groups, the other for better-organized or large-scale tasks.

[Lamech]

Just square everything add it and square root it, if you want combined strength without fiddling with basic lifts. You need an Excel, but its pretty easy if you have that.

[smurf]

One person pushing a car is hard.
Two people is a bit easier
Three people is the limit due to the size of the car.

IMO you would combine the ST.

Like tug o war you would combine and make tests vs grip and stance. Traditionally the largest person is the anchor and uses steps to take up the slack by the tuggers.