Reading the roll-under thread got me thinking about a system, like BRP's, where skills are based on percentages. However, rather then take the skill's percent chance of success straight and try to roll under it, during chargen the percent chance of failure would be derived and during play a roll-over the failure chance would be used. So the guy that has a firearms of 80 would have a 20% chance of missing and would try to roll over that. Seems like it would be the same odds, but would fix the hang-up some folks have with roll-under / subtraction. Have any games already done this, and if they have does it work ok? Just a thought. Then opposed rolls would just be either highest roll, or the character that achieves the highest margin. Very little difference than the roll-under, but perhaps a touch more intuitive. Any pitfalls to this approach?

Don't see a big problem with it, Chris. You couldn't derive a Quality of Success from it though - otherwise tyros would always succeed big if they succeed at all, and the chance of getting a marginal success would increase with your skill rank. Not a big deal though - most games have a separate Quality roll.

-clash

Couldn't the quality of your success be derived from how much you beat your chance of failure by? It seems to me it's functionally no different than the roll-under system, just reversed. so instead of the 80 firearms guy trying to roll under 80%, he's trying to roll over 20%. it's just reverseing the failure chance from the top of the spectrum to the bottom, but as far as I can tell the odds, and indeed the system itself, is functionally identical. Am I wrong? I'm certainly no mathematician or game designer.

So, once again using the 80 firerms guy, his margins could be derived from his miss chance. Say, 5% for just barely succeeding nd 20% for marginally succeeding. If our guy rolls 23 to hit, he hits but just barely... maybe nicking the target. He rolls 32 and pretty much just hits center-mass without hitting anything vital... a basic hit. then, rolling 00 means is always a high quality success so that even someone with only a 15 in a skill can get lucky and achieve a great success.

Quote from: Sigmund;520800Reading the roll-under thread got me thinking about a system, like BRP's, where skills are based on percentages. However, rather then take the skill's percent chance of success straight and try to roll under it, during chargen the percent chance of failure would be derived and during play a roll-over the failure chance would be used. So the guy that has a firearms of 80 would have a 20% chance of missing and would try to roll over that. Seems like it would be the same odds, but would fix the hang-up some folks have with roll-under / subtraction. Have any games already done this, and if they have does it work ok? Just a thought. Then opposed rolls would just be either highest roll, or the character that achieves the highest margin. Very little difference than the roll-under, but perhaps a touch more intuitive. Any pitfalls to this approach?

One of our CoC GMs sometimes handled skill rolls like that. We never had a problem with it, but then we're really used to roll-under stuff as well.

Quote from: The Butcher;520825One of our CoC GMs sometimes handled skill rolls like that. We never had a problem with it, but then we're really used to roll-under stuff as well.

Me too. My two favorite game systems, d100 and GenreDiversion, use roll-under. I think Clash's percentile variant for SC3 is roll-under as well, but I haven't played that variant yet. I might give this flipped-over approach to d100 a try though.

Quote from: Sigmund;520811Couldn't the quality of your success be derived from how much you beat your chance of failure by? It seems to me it's functionally no different than the roll-under system, just reversed. so instead of the 80 firearms guy trying to roll under 80%, he's trying to roll over 20%. it's just reverseing the failure chance from the top of the spectrum to the bottom, but as far as I can tell the odds, and indeed the system itself, is functionally identical. Am I wrong? I'm certainly no mathematician or game designer.

Then you'd have to do a subtraction - taking the chance of failure from the roll - every time to get the actual quality. It's clumsy and non-intuitive. The odds are precisely the same, as you said, but there's that extra step...

Quote from: Sigmund;520811So, once again using the 80 firerms guy, his margins could be derived from his miss chance. Say, 5% for just barely succeeding nd 20% for marginally succeeding. If our guy rolls 23 to hit, he hits but just barely... maybe nicking the target. He rolls 32 and pretty much just hits center-mass without hitting anything vital... a basic hit. then, rolling 00 means is always a high quality success so that even someone with only a 15 in a skill can get lucky and achieve a great success.

This is exactly what I was talking about, Chris. If a tyro succeeds, he succeeds BIG! He cannot just barely succeed. On the other hand, the very competent have a bigger and bigger possibility of a poor quality of success as their skill increases - though the chance of inflicting *some* damage increases as well. If this is the effect you want, then cool - just be aware of it.

clash

Quote from: Sigmund;520828Me too. My two favorite game systems, d100 and GenreDiversion, use roll-under. I think Clash's percentile variant for SC3 is roll-under as well, but I haven't played that variant yet. I might give this flipped-over approach to d100 a try though.

StarPerc - the percentile mechanic variant for StarCluster 3 - uses a two-roll system. The Chance roll is a binary roll - it doesn't matter how much you succeed by, it's just pass/fail, roll lower than or equal to TN. The second roll - also on percentiles - is a Quality roll. It's a straight up, higher is better roll. Anyone who succeeds has the same chance to get either a high or low quality. Most of the other variants work off a difference mechanic on a single roll, so that higher skill ranks give higher potential quality.

-clash

Actually - I like it. It does a different thing in a different way, Chris. I will add it to the available StarCluster mechanics after playing with it.

Want to name it? Start with "Star" - like StarPerc, StarPool, Star20, StarRisk, and the rest.

-clash

Quote from: flyingmice;520829Then you'd have to do a subtraction - taking the chance of failure from the roll - every time to get the actual quality. It's clumsy and non-intuitive. The odds are precisely the same, as you said, but there's that extra step...



This is exactly what I was talking about, Chris. If a tyro succeeds, he succeeds BIG! He cannot just barely succeed. On the other hand, the very competent have a bigger and bigger possibility of a poor quality of success as their skill increases - though the chance of inflicting *some* damage increases as well. If this is the effect you want, then cool - just be aware of it.

clash

I don't think I'm understanding what you are saying here. I don't see how someone wth higher skill has less chance of a good success. A guy with firearms 80 has a 20% chance to miss, a 5% chance to just barely succeed, a 15% chance to marginally succeed, and 60% chance to succeed quite well. A guy with firearms 20 has an 80% chance to fail, a 5% chance to just barely succeed,  15% chance to marginally succeed, and virtually no chance to succeed quite well. Maybe the 1% if one is playing with the 00 equals always a "crit". Not sure how any of this is any more non-intuitive than any other percentile system, and certainly not how it's less intuitive than roll-under.

Quote from: flyingmice;520837Actually - I like it. It does a different thing in a different way, Chris. I will add it to the available StarCluster mechanics after playing with it.

Want to name it? Start with "Star" - like StarPerc, StarPool, Star20, StarRisk, and the rest.

-clash

Heh, let me think on it.

All I can think of is "starflip" because it's basically a flipped over percentile system, or "starmiss" because it's based on your "miss" or failure chance rather than your success chance.

With a percentile system, subtraction always has to be done. This percentile system gets the subtraction done during chargen or character advancement, when the numbers get recorded on the character sheet, and then it's just a straight roll-over system. There has to be more to it than this though... something I'm missing.

How about Star100 or StarOver?

-clash

Quote from: flyingmice;521192How about Star100 or StarOver?

-clash

Star100 is perfect