I am considering a change with Unisystem from 1D10 to 2D6. I know Vortex uses that version. Why would you prefer 2D6? Is it the normal curve? Doesn't it become easier for skillfull characters in the long run?

I prefer 2d6 because of the curve. It makes sense for more skilled characters to have an easier time in the long run.

The more dice you have, the more likely you're going to hit a median.  If the system rewards that, you want to use it.

I DM'd a 2d6 session tonight.  I actually witnessed a lot of failing rolls.  Because of the party being small; I played a PC, with no favoritism.  My PC was the first to die.

Quote from: jan paparazzi;1081613I am considering a change with Unisystem from 1D10 to 2D6. I know Vortex uses that version. Why would you prefer 2D6? Is it the normal curve? Doesn't it become easier for skillfull characters in the long run?

I prefer 2D6 because it has a curve. But there is much more to a 2D6 roll than just its curve. Most 2D6 games are crap when it comes to target numbers, modifiers, levels of successes and failures. Which is why most D6 systems are crap.

Quote from: Shawn Driscoll;1081625I prefer 2D6 because it has a curve. But there is much more to a 2D6 roll than just its curve. Most 2D6 games are crap when it comes to target numbers, modifiers, levels of successes and failures. Which is why most D6 systems are crap.

I figured the target number with 2D6 should be 10 or 11 instead of 9, because the average of 2D6 = 7 instead of 1D10 = 5,5. Or I could do 3D6 = 10,5 and the target number should be 14 (+5) in that case. Exploding dice is a thing.

Why did the Pundit recommend 2D6 instead of 1D10 for Rocket Age? I already decided to go for 2D6, but I am curious.

Quote from: Shawn Driscoll;1081625I prefer 2D6 because it has a curve. But there is much more to a 2D6 roll than just its curve. Most 2D6 games are crap when it comes to target numbers, modifiers, levels of successes and failures. Which is why most D6 systems are crap.

Even Traveller?

Quote from: jan paparazzi;1081613I am considering a change with Unisystem from 1D10 to 2D6.

Unisystem was in that weird place where Storytelling System was killing it because of WOD and, as a result, 1d10 was considered what they needed to use to keep things "simple". Unfortunately, the system was in bogged down in stupid shit like analysis paralysis in areas core areas like skills -- it rendered the attempt at being "accessible" redundant. Changing the dice system may cause more headache than it's worth.

Quote from: jan paparazzi;1081613Why would you prefer 2D6? Is it the normal curve? Doesn't it become easier for skillfull characters in the long run?

I don't. 1d10 all the way. I prefer lethality and immediacy of rewards for stat upgrades in my games.

People have already mentioned the curve but they're understating it. The more dice you add, the higher the chance of getting a mediocre result. Same reason they do "roll 4d6, drop lowest": shitty results are common. You tend to get 9-12/13(ish) but nothing spectacular (or useful).

With 1d10, if someone has 3 or more points above you in a stat, you're freaking the fuck out because their PC is much more likely to blow your head off than the reverse in any given situation, everything else being equal. It encourages specialization more readily. It discourages getting into shit you have no business getting into.

Quote from: jan paparazzi;1081637I figured the target number with 2D6 should be 10 or 11 instead of 9, because the average of 2D6 = 7 instead of 1D10 = 5,5. Or I could do 3D6 = 10,5 and the target number should be 14 (+5) in that case. Exploding dice is a thing.

If you are going with exploding dice. Then maybe bell curves are not needed for a die mechanic.

Quote from: Aglondir;1081976Even Traveller?

With some editions, yes.

Quote from: PrometheanVigil;1082094People have already mentioned the curve but they're understating it. The more dice you add, the higher the chance of getting a mediocre result. Same reason they do "roll 4d6, drop lowest": shitty results are common. You tend to get 9-12/13(ish) but nothing spectacular (or useful).

Too many dice will make a curve useless for a die mechanic. Probably better to go with a dice pool method instead.

Quote from: PrometheanVigil;1082094People have already mentioned the curve but they're understating it. The more dice you add, the higher the chance of getting a mediocre result. Same reason they do "roll 4d6, drop lowest": shitty results are common. You tend to get 9-12/13(ish) but nothing spectacular (or useful).

Too many dice will make a curve useless for a die mechanic. Probably better to go with a dice pool instead method.

Quote from: PrometheanVigil;1082094People have already mentioned the curve but they're understating it. The more dice you add, the higher the chance of getting a mediocre result. Same reason they do "roll 4d6, drop lowest": shitty results are common. You tend to get 9-12/13(ish) but nothing spectacular (or useful).

That is not the right way to look at it. It's not so much about the dice not deviating enough from the expected value, at least not with 2 or 3 dice. Once the finally value you roll against is set, the die make no difference. Whether you roll d100 versus 74% or 3d6 versus 12 (74.07% chance to pass) makes practically no difference. Instead, it's about the effect of modifiers, including stat/skill advancement. A +10% bonus in a d100 system behaves differently from a +1 bonus in GURPS.

The easiest way to realize this, shameless plug, is in the "Bell-curved d100" in my own RPG (note the difference in success chance between a +1 CL below versus a flat +10% for straight d100s):




And here's a final thought: the less frequent a "useful" result is, the more spectacular it is. Rolling a 12 on 2d6 is 3.6 times more spectacular than rolling a 10 on d10.

To be clear: this is not about the chance of succeeding a roll. It's about the fact you have a higher chance of rolling a 6, 7 or 8 with 2D6. This will mean that you probably have a bigger chance of making a roll with higher stats and 2D6 vs higher stats and 1D10. And probably have a smaller chance of making a roll with lower stats and 2D6 vs 1D10. Characters will become even more specialized with 2D6 vs 1D10.

Quote from: jan paparazzi;1081637I figured the target number with 2D6 should be 10 or 11 instead of 9, because the average of 2D6 = 7 instead of 1D10 = 5,5. Or I could do 3D6 = 10,5 and the target number should be 14 (+5) in that case. Exploding dice is a thing.

On a d10 the chance of rolling a 9 or 10 is 20%.  Even if you explode on a 10, it won't matter if you need a 9 or 10.  

On 2d6, the chance of rolling an 11 or better is 25% assuming independent exploding on a 6.    

On 2d6, the chance of rolling a 10 or better is 30% with exploding.

If you remove exploding, the chance of rolling an 11 or 12 is only 8%; a 10+ is only 17%.  If you make success happen on a 9, the odds go up to 28%.

Effectively, 2d6 does not correlate well to a d10.  If you opt for 2d6, you should consider what you're trying to do and why.  Effectively, you make a median result more likely compared to extreme results; if median results do not equate to success, you're not really helping anyone.  

If you choose independently exploding d8s, 2d8 against a target of 14 is roughly equivalent to 1d10 against a target of 9+ (21.09%).

Quote from: jan paparazzi;1082291To be clear: this is not about the chance of succeeding a roll. It's about the fact you have a higher chance of rolling a 6, 7 or 8 with 2D6. This will mean that you probably have a bigger chance of making a roll with higher stats and 2D6 vs higher stats and 1D10. And probably have a smaller chance of making a roll with lower stats and 2D6 vs 1D10. Characters will become even more specialized with 2D6 vs 1D10.

I was pointing out above that this is not the case. Let's think through it logically: a bell-curve means diminishing returns at the upper end - does this induce greater specialization or does it dissuade investments into having an even higher stat level... higher by a slight margin? It clearly is the latter. When you have reached a 75% skill, it becomes harder and harder to make any significant improvements and you're probably better off using your resources to improve other, lower skills by greater amounts.