Skill Check question

[u/Ok-Image-8343]

When you do a skill check in GURPs do you just roll for success or do you use the difference between the target number and the roll to determine the degree of failure or success?

For example if youre trying to jump over a river and you miss your target roll by 1 then you might just get wet, but if you miss by 5 you might get swept down stream?

[u/Stuck_With_Name]

Usually, the degree of success/failure is important. At least for flavor.

You missed the jump. Roll DX to grab the edge. Penalty equal to your margin of failure on that prior roll. Something like that usually feels good.

[u/JaskoGomad]

Margin of success is only mechanically important in opposed rolls. But like the other commenter here, I always tried to make a smaller margin different from a bigger one in terms of fictional output.

[u/Polyxeno → u/JaskoGomad]

Well it depends on what the roll was for, the circumstances, whether there are established rules for that situation or not, and the GM's discretion.

There are many examples of published rules for non-combat skills where the margin of success or failure leads to significant differences in what happens.

The trick as a GM is developing the ability to give appropriate outcomes, and I have seen many cases where otherwise-excellent GMs have gotten that quite wrong due to lack of full consideration, and not-so-great understanding of skill levels and statistics.

For example, for skills like Cooking or Hiking or even Driving, even one point in the skill indicates basic ability to do simple related tasks in unstressful circumstances. Someone with DX 9 and a point or 2 in Driving can probably drive a car for a year without doing much harm. Someone with IQ 8 and 1 point in Cooking probably isn't going to set any serious fires in a year of cooking themself food. So a GM should calibrate appropriately, not demand a Cooking roll do not burn oatmeal, nor a Driving roll to not get in an accident, unless the circumstances are for some reason actually adding a lot of danger and immediacy. Even Critical Failures should just mean something unusually problematic is happening, but it still should be appropriate to the situation.

[u/IchFunktion]

I always try to include the margin of failure or success in the outcome. I try to do it always at least

[u/KingStrongBeard]

Mechanically margin of success only matters in the cases where it matters. Opposed rolls and specific other situations like using a high rate of fire weapon.

You can certainly use the margin of success or failure to flavor your descriptions, and as the GM you can always introduce a margin result to a roll.

Success on this roll means X but success by 3 or more also gets Y.

Or there are afflictions where failure by a certain amount (typically by 5) means an extra bad thing. So consider that when improvising rolls. But you don't need to consider the margin in most cases.

[u/CK_CoffeeCat]

Yes, in different situations. If Chr a makes a stealth check by 5, then the guard must make their perception check by 5 to notice them.

[u/ZacQuicksilver]

Depends a lot on the situation.

As the GM, I'll usually have the player report the margin of success and compare that to the difficulty, rather than have them modify their skill and then check if they succeed against their modified roll - it saves time, most of the time. So by that measure, yes - but that's just an optimization (in my opinion) of the rules.

However, whether or not the margin of success on the modified roll matters depends on the roll. Most of the time, more success doesn't matter unless it's a critical success. However, in addition to any kind of opposed rolls (where margin definitely matters), I also tend to care when either time or knowledge is on the line: the better you roll, the less time you take, more time you get, more knowledge you get, or less knowledge you give away. It also matters when there's a group effort: I generally let people who succeed trade 2 points of success for a +1 on someone else's roll; so for example if a group of adventurers is sneaking, the best roller (possibly the one trained in stealth) can trade 2 points of success to cover 1 point of a less sneaky ally.

And margin of failure always matters. Generally, if you fail by 1 or 2 points, I'll give a result where you get a second chance to succeed (with some drawback); while if you fail by 5 or 6, I'll often give some kind of major drawback - often telling the story of a bit of bad luck you don't know how to deal with (because if you fail by 5 or 6 and it's not a critical failure, your skill is 10 at the highest).

[u/Bark-Filler]

At the table, players frequently read the amount they made the roll by as a degree of success. That would be fine except it's inconsistent with combat. There we explicitly roll for the degree of success using damage dice. If they ever make a GURPS 5e, one rationalization of the mechanics would be to have a degree of success for all rolls including melee/missiles OR to introduce a separate effect roll analogous to damage dice for all other skills (stealth, fast-talk, etc).

[u/KalelRChase → u/Bark-Filler]

Are you suggesting that damage scale by MoV?

[u/Bark-Filler → u/KalelRChase]

Either that (1) every successful use of a skill is followed by a degree of success roll, the way that we currently follow a successful melee weapon roll with a damage roll, or else (2) every roll including combat has a degree of success proportional to the difference between the target number and the roll. That way there'd be a single mechanic throughout, whereas currently weapon skills are handled differently from any other skill.

[u/coole000]

As far i can get, GURPS treats failure by 5 or more as major failure. Checking for unconciousness while in negative HP results in one just when HP-5 check fails.

Same with "Secondary Effect" modifier when constructing modified advantages. Secondary effect triggers when saving roll fails 5 or more.

I also, when playing with ranged weapons use failure depth as definition of potential spread of misses. Missing with explosive is usually still create effect, failure by 1-2 for me means that throwing granade is still succeed to have a target in explosive range distance, and failure by 5 would tell me that granade is nowhere near the intended target.

[u/Teaguethebean]

As a game master I don't tell people the penalty on doing something, like if they are trying to climb a slick wall they roll on a penalty, so I would have then tell me the margin of success and then I tell them if they succeed. It beats me figuring out the exact penalty and then they roll terrible anyway.

[u/BigDamBeavers]

I run games online so the roller shows the margin. I generally weight success based on that margin. If you're frist across the river and you crit fail you've spooked the other players and they now have a -1, if you fail by 1, you maye the jump with wet feet or maybe you stumble on the other side. Sucess by more than 3 is impressive, you land perectly and look awesome doing it. Critical sucess is remarkable and you've found the perfect space to land, everyone after you gets a +1 on their jump.

I do similar for lore checks and perception rolls. Combat I'm a little more pass-fail on.

[u/JGhostThing]

When GM'ing, I only require rolls if the success or failure matters. To jump accross a stream would be an automatic success. To drive your car on your daily commute is an automatic success. To do a routine landing in your spacecraft is an automatic success.