Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 01-30-2016, 09:56 PM   #1
Flinx
 
Join Date: Jan 2016
Default Success rolls: effective skill below 3

Hello,

I am in the process of learning the basic rules and have just stumbled on the following (B345):
Quote:
You may not attempt a success roll if your effective skill is less than 3, unless you are attempting a defense roll […]
It is not that this rule is not clear, I am just wondering why it exists and if I am overlooking any implications. Except for defense rolls as mentioned, this reduces the rule “3 and 4 are always a success” to “if your effective skill is 3, 4 is also a success”. And the odds for effective skills below 3 are so discouraging that it seems pointless to forbid it. If a player wanted to try something with an effective skill of e.g. 1, as a GM I would just say “You know this has only a 1.85% chance of success and a 50% chance of a critical failure, are you sure?”

But perhaps I am missing something here. Let me know if you think this is a rule that can be ignored without any impact.

Last edited by Flinx; 01-30-2016 at 10:02 PM. Reason: Typo in title; also added tag to title
Flinx is offline   Reply With Quote
Old 01-30-2016, 10:47 PM   #2
Curmudgeon
 
Join Date: Sep 2011
Default Re: Success roles: effective skill below 3

Quote:
Originally Posted by Flinx
It is not that this rule is not clear, I am just wondering why it exists and if I am overlooking any implications. Except for defense rolls as mentioned, this reduces the rule “3 and 4 are always a success” to “if your effective skill is 3, 4 is also a success”. And the odds for effective skills below 3 are so discouraging that it seems pointless to forbid it. If a player wanted to try something with an effective skill of e.g. 1, as a GM I would just say “You know this has only a 1.85% chance of success and a 50% chance of a critical failure, are you sure?”

But perhaps I am missing something here. Let me know if you think this is a rule that can be ignored without any impact.
The rule probably exists because it isn't physically possible to roll less than 3 on 3d6. Since it is effective skill we are talking about, it isn't unreasonable to say that you should have no chance of success if the situation reduces your skill to less than 3. Otherwise you would be allowed the possibility of getting lucky and rolling a critical success on a 3 or 4, 2% of the time, and not only being successful but wildly successful, which doesn't quite seem fair. Even allowing a non-critical success on a roll of 3 with a 4 being a failure is a bit of a stretch, though not as bad a one. The key to remember is that a 2% chance of success is, on average, a success once every fifty tries. A success on a 3 would be bit less frequent, about once in 200 tries for rough figuring.

That said, it doesn't seem likely to break the game if you ignore the rule but you do need to determine whether success that often, under conditions that adverse, is going to break your suspension of disbelief.

The other thing to consider is that you've essentially opened the door for rolls when effective skill is reduced to 0 or a negative number. The argument can be made (and has a certain mathematical validity),that if you allow a roll for impossible results like a 1 or 2, you should also permit them for the equally impossible values of 0 and -1, for example.
Curmudgeon is offline   Reply With Quote
Old 01-30-2016, 11:46 PM   #3
ArchonShiva
 
Join Date: Sep 2004
Location: Montréal, Québec
Default Re: Success roles: effective skill below 3

Yeah, mostly it's so you can't succeed 1-in-50 with effective skill -2714.

Other than that, feel free to ignore it. GURPS is a tool box.
ArchonShiva is offline   Reply With Quote
Old 01-31-2016, 12:42 AM   #4
Flinx
 
Join Date: Jan 2016
Default Re: Success rolls: effective skill below 3

Quote:
Originally Posted by Curmudgeon View Post
The rule probably exists because it isn't physically possible to roll less than 3 on 3d6.
But the same can be said about the other end of the scale. Since all effective skills above 16 are treated like 16, it would be consistent to say all effective skill below 4 are treated like 4.

Quote:
Originally Posted by Curmudgeon View Post
Since it is effective skill we are talking about, it isn't unreasonable to say that you should have no chance of success if the situation reduces your skill to less than 3. Otherwise you would be allowed the possibility of getting lucky and rolling a critical success on a 3 or 4, 2% of the time, […]
Fair enough. For me the idea that you always have a slim chance of success was already ingrained when I came upon this “no chance below 3” rule, which might explain my unease about it. But there are also two aspects of the rules that to me make this limit seem inconsistent:
  1. Cases of “zero chance that you can do this” are already covered by skills without defaults.
  2. For the purpose of defense rolls the official standpoint is precisely that you can succeed with an abysmal effective skill.

Quote:
Originally Posted by Curmudgeon View Post
[…] and not only being successful but wildly successful, which doesn't quite seem fair.
This is an interesting point I had not thought about. On the other hand the rules consider 3 and 4 a critical success even if your effective skill is only 3 or 4. So the idea behind it seems to be that a success is critical because it is a rare kind of success, not because it is far better than necessary. (Although that is somewhat contradicted again by 5 and 6 becoming critical successes for effective skills of at least 15 and 16 respectively.)

Quote:
Originally Posted by Curmudgeon View Post
The other thing to consider is that you've essentially opened the door for rolls when effective skill is reduced to 0 or a negative number. The argument can be made (and has a certain mathematical validity),that if you allow a roll for impossible results like a 1 or 2, you should also permit them for the equally impossible values of 0 and -1, for example.
Of course; and this is exactly what the rules do in case of defense rolls.

I guess this quickly becomes more a discussion about game design than about application of rules. I am inclined to leave out the rule when explaining the mechanics in favor of simplicity and consistency. Should a player ever want to try their luck I will hand out hard consequences for a critical failure and warn them about it.

Thank you for your thoughts on the topic.
Flinx is offline   Reply With Quote
Old 01-31-2016, 12:50 AM   #5
roguebfl
Dog of Lysdexics
 
roguebfl's Avatar
 
Join Date: Oct 2004
Location: Melbourne FL, Formerly Wellington NZ
Default Re: Success rolls: effective skill below 3

Quote:
Originally Posted by Flinx View Post
But the same can be said about the other end of the scale. Since all effective skills above 16 are treated like 16, it would be consistent to say all effective skill below 4 are treated like 4.
Which is why Skill level 16 opens the option of "No Nuisance rolls" perk for the skill.
__________________
Rogue the Bronze Firelizard
Gerald Grenier, Jr. Hail Eris!
Rogue's Weyr
roguebfl is offline   Reply With Quote
Old 01-31-2016, 02:56 AM   #6
Flinx
 
Join Date: Jan 2016
Default Re: Success rolls: effective skill below 3

Quote:
Originally Posted by roguebfl View Post
Which is why Skill level 16 opens the option of "No Nuisance rolls" perk for the skill.
This seems to cover scenarios where the GM would probably waive the rolls anyway, but I guess that’s why it’s just a perk. (In case anyone else is looking for the description, it’s in “Power-Ups 2: Perks”.)

As a matter of principle I think that if a roll is appropriate at all, it’s interpretation should be true to the normal distribution it approximates, which includes only asymptotically approaching zero in both directions and so always leaving a slight chance of both success and failure under all circumstances. And on a more practical note it just makes for a better gaming experience. If a character who has never used a bow wants to pick one up and shoot an opponent’s eye out, I don’t want to say „you can’t do that“, I want to say „you can certainly try but there is a high chance you will hit one of your companions instead”.
Flinx is offline   Reply With Quote
Old 01-31-2016, 04:00 AM   #7
Nereidalbel
 
Join Date: May 2013
Location: Ellicott City, MD
Default Re: Success roles: effective skill below 3

If somebody using Bow at default wants yo shoot somebody in the eye, they should end up with at least an effective skill of 3 by using a full Aim.
Nereidalbel is offline   Reply With Quote
Old 01-31-2016, 11:40 PM   #8
PK
Assistant GURPS Line Editor
 
PK's Avatar
 
Join Date: Aug 2004
Location: Dobbstown Sane Asylum
Default Re: Success rolls: effective skill below 3

Quote:
Originally Posted by Flinx View Post
Let me know if you think this is a rule that can be ignored without any impact.
Definitely not.

Imagine a group of PCs with unimpressive Guns skills (say, 10 to 12) who need to snipe a quickly moving target through the eye from a little under a mile away.

Even with a decent sniper rifle, the shooter's effective skill would be at +6 (Acc) +2 (full Aim) -18 (range) -9 (eye) = -19 to skill. There are expanded rules to get a slightly better bonus, but the point is he's definitely in the negatives.

Now let's say your house rule would let him succeed on a 3-4 even if he's negative. Why bother with the nice sniper rifle, if he's probably going to critically fail anyway?

Instead, he takes a box full of cheap pistols up onto the roof and starts having his friends hand him one, he shoots it, it explodes or jams (good thing he's wearing armor), and so he shoots another one. At this rate, he can fire once every two seconds, so he'll put a bullet through his target's eye in (on average) just under a minute.

The target is moving at supersonic speeds? No problem, because his chance to hit is the same. The target is actually a tiny transmitter (SM -10)? Same chance to hit. The shooter is operating in pitch black darkness? Just another -10, same chance to hit.

That's the problem with establishing an "auto-win" situation. No matter how likely it makes a critical failure, it also means that (A) past a certain point, penalties mean nothing, and that (B) because literally anything can succeed, there's no reason not to keep trying again and again.
__________________
Reverend Pee Kitty of the Order Malkavian-Dobbsian (Twitter) (LJ)

MyGURPS: My house rules and GURPS resources.

#SJGamesLive: I answered questions about GURPS After the End and more!
{Watch Video} - {Read Transcript}
PK is offline   Reply With Quote
Reply

Tags
rules

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 02:28 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.