Game mechanic purupse of xd6 roles

[sekalo]

At first I was confused when to use modifiers or the xd6 rolls; however, I have been pushing forward working with my group and TFT powered game.

However, I started to wonder what purpose in game mechanics does xd6 provide over the -x bonus/penalty modifiers on rolls? It seems like skills/talents use the xd6 dice rolls while combat uses the -x modifiers. Why not keep it uniformed and just use one or the other.

[hcobb]

The real confusion arises when one rule says that on a roll of 18 such and such occurs and then another rule say to roll more or fewer dice.
The big advantage of adding more dice is that this greatly increases the risk of a critical failure. It is easier to hit with an untalented weapon in daylight than if talented and fighting in the dark, but you are more likely to break the weapon also. At least you'll be able to see where the broken bits of your sword fall.

[TippetsTX]

Didn't we cover this topic sufficiently in this previous thread?

https://forums.sjgames.com/showthread.php?t=199146

[sekalo]

Originally Posted by TippetsTX

Didn't we cover this topic sufficiently in this previous thread?

https://forums.sjgames.com/showthread.php?t=199146

Yes we sort of did for in game mechanics and when to use what, etc; however, the concept is fascinating to me - compared to GURPS, which just changes dice bonus/penalties.

The concept of changing the number of dice to roll is very interesting to me, and I was curious as to why this method was selected over just changing the bonus/penalties.

The root of TFT started way before GURPS; however, we see the multi dice rolls dropped with GURPS. Due to the latter, what purpose does the multidice rolls serve? Speculation, why was it not carried over to GURPS? What different benefits from a game mechanics does it provide then just giving or taking away values on dice rolls or skills?



I have more experience with Traveller and Battletech/Mechwarrior - so the idea of adding or removing dice was a hard concept to understand when you also had bonus/penalties on target numbers/skill.

The only other game I have played that add/removed dice was Star Wars D6; however, it only had the dice add/remove concept, and did not mix. This is why (other post you pointed at) made it so hard for me to understand when to do what or how.

[TippetsTX]

Originally Posted by sekalo

The concept of changing the number of dice to roll is very interesting to me, and I was curious as to why this method was selected over just changing the bonus/penalties.

The root of TFT started way before GURPS; however, we see the multi dice rolls dropped with GURPS. Due to the latter, what purpose does the multidice rolls serve? Speculation, why was it not carried over to GURPS? What different benefits from a game mechanics does it provide then just giving or taking away values on dice rolls or skills?

The only explanation (though I'm not sure that you can really call it that) that we get from the author is the following text on pg 8 of In the Labyrinth.

"More dice are added if the task is difficult. Dice may be subtracted if you are using an appropriate skill. The success roll is the biggest game mechanic in your GM toolkit. By deciding what stat the character is rolling against, and whether dice are added or subtracted to the basic 3, you can adjust the difficulty of any task to what you feel is fair."

In other words, the number of dice defines the task's inherent difficulty.

GURPS chooses not to make a mechanical distinction between inherent and incidental difficulty, but many RPG systems do. Most of them set a target value (that the player rolls against) which is the measure of action difficulty and then will apply modifiers to that roll based on various factors like skill or situational conditions. In d20 games, for example, you have AC or CR that you have to beat with a modified die roll. TFT and GURPS, on the other hand, make you roll against the character’s ability (usually DX), not the task itself.

I don't know if Steve ever explained his reasoning for dropping the add/subtract dice feature from GURPS, but I prefer the way TFT does it, TBH.

[Shostak]

Originally Posted by TippetsTX

The only explanation (though I'm not sure that you can really call it that) that we get from the author is the following text on pg 8 of In the Labyrinth.

GURPS chooses not to make a mechanical distinction between inherent and incidental difficulty, but many RPG systems do. Most of them set a target value (that the player rolls against) which is the measure of action difficulty and then will apply modifiers to that roll based on various factors like skill or enforced conditions. In d20 games, for example, you have AC or CR that you have to beat with a modified die roll. TFT and GURPS, on the other hand, make you roll against the character’s ability (usually DX), not the task itself.

I don't know if Steve ever explained his reasoning for dropping the add/subtract dice feature from GURPS, but I prefer the way TFT does it, TBH.

GURPS success rolls are made against a target defined by skill+modifiers, and those modifiers are very often negative. So, GURPS definitely uses situational difficulty.

[TippetsTX]

Originally Posted by Shostak

GURPS success rolls are made against a target defined by skill+modifiers, and those modifiers are very often negative. So, GURPS definitely uses situational difficulty.

But my point is that the target you are rolling to beat is defined by an attribute (ST, DX, etc.), not the task or action itself. Skill and difficulty are both factors that apply modifiers to the attribute value, but GURPS doesn't use task difficulty as the target.

[Shostak]

The target is defined as much by the modifiers as it is by the skill level. One begins with the skill level and then applies modifiers to it. That is fundamentally different from simply rolling against the skill level.

[sekalo]

Topics like these are always fun for me, since I like to review and look at the game mechanics and design features.

I used "anydice", and not sure if I did it correctly, but if we take the average on a 3d6 roll it is roughly 10-/50%. If subtract a dice for 2d6 that 50% becomes a 7. Now if we add a dice 4d6 50% is a 14-. So I guess a -4 penalty would give us roughly the same probability with 3d6 dice. 5d6 would roughly be a -6 on 3d6.

Now if we just ignore the critical thresholds that move when adding/removing dice - we can get a rough simulation based on the following

Average target is 10
2d6 = +3/+4 to skill/attribute on 3d6 rolls
3d6 = 0 base target of 10
4d6 = -3/-4 to skill/attribute on 3d6 rolls
5d6 = -6 to skill/attribute on 3d6 rolls

By using those values - a target number of 10 has the same or roughly same percentage chance on 3d6 as it does on the multi dice approach.

I do not know how to do it with AnyDice, but I would love to see what roll #d6 and keep highest out of 2 or 3 looks like.

[Shostak]

Originally Posted by sekalo

Topics like these are always fun for me, since I like to review and look at the game mechanics and design features.

I used "anydice", and not sure if I did it correctly, but if we take the average on a 3d6 roll it is roughly 10-/50%. If subtract a dice for 2d6 that 50% becomes a 7. Now if we add a dice 4d6 50% is a 14-. So I guess a -4 penalty would give us roughly the same probability with 3d6 dice. 5d6 would roughly be a -6 on 3d6.

Now if we just ignore the critical thresholds that move when adding/removing dice - we can get a rough simulation based on the following

Average target is 10
2d6 = +3/+4 to skill/attribute on 3d6 rolls
3d6 = 0 base target of 10
4d6 = -3/-4 to skill/attribute on 3d6 rolls
5d6 = -6 to skill/attribute on 3d6 rolls

By using those values - a target number of 10 has the same or roughly same percentage chance on 3d6 as it does on the multi dice approach.

I do not know how to do it with AnyDice, but I would love to see what roll #d6 and keep highest out of 2 or 3 looks like.

I recall having read that a feature of adding more dice is that the likelihood of rolling very close to the average expected value increases as the number of dice increases.