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Old 11-24-2018, 03:11 PM   #1
bactram1
 
Join Date: Jun 2012
Default The 3D - 4D - 5D Heresy

Die rolls in TFT are based on bell curves, usually 3D6. But when the going gets tough, you don’t adjust the result of the die rolls, instead you just roll more dice. The bell curve for 4 dice is much higher than 3 dice. The average roll on 3D6 is 10.5, and an adjusted skill level of 10 will succeed 50% of the time. But on 4 dice that changes to 15.9%. That seems like excessively harsh. If you go to 5 dice the chance of success if your skill level is 10 is 3.24%.

Now, when SJ lost the rights to TFT, he started working on the Great Unnamed Role Playing System (AKA GURPS, I remember the great reveal that changed “Great Unnamed” to “Great Universal”). At this time SJ changed to using 3D6 for all rolls, and adjusted the results by +1, -2, or something. Still keeping an adjusted skill level of 10, 3D6 is still 50%. Adding 1 to the die results (an adjusted skill level of 9) gives 37.5%, +2 gives 25.93%, and +3 gives 16.2%. These odds seem more reasonable. It’s almost as if SJ was using experience from TFT to the design of GURPS.

Now that SJGames bought the rights to TFT, reviving a beloved game from my youth, we’re back to adding dice. While it’s easy enough to house-rule 4D6 to 3D6+1 and 5D6 to 3D6+2, I’d like to see something official on this. I think it’s just too much for 50% odds to change to 15.9%. I know that SJ will probably be against this, which is why I’m calling it a heresy. SJGames could have a PDF that says: If the GM wants to change the odds of very hard feats he may want to change 4D to 3D6+2, and 5D to 3D6+3. There can be tables showing the effect this would have.

What do you think?

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I got the percentages from https://anydice.com/program/9350
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Old 11-24-2018, 06:09 PM   #2
Skarg
 
Join Date: May 2015
Default Re: The 3D - 4D - 5D Heresy

Quote:
Originally Posted by bactram1 View Post
Die rolls in TFT are based on bell curves, usually 3D6. But when the going gets tough, you don’t adjust the result of the die rolls, instead you just roll more dice.
...
Still keeping an adjusted skill level of 10, 3D6 is still 50%. Adding 1 to the die results (an adjusted skill level of 9) gives 37.5%, +2 gives 25.93%, and +3 gives 16.2%. These odds seem more reasonable. It’s almost as if SJ was using experience from TFT to the design of GURPS.
That's not an accurate picture of TFT, though. SOME things that are supposed to be significantly more difficult require a 4-die or 5-die roll in TFT, but TFT also has various difficulty modifiers that can be as little as +/- 1 point, so that's not a new ability that GURPS introduced.

Now, I do think some house-rulers, and perhaps some of the new edition's rules, have a tendency to jump too quickly to "just add or subtract another die" mechanics without analyzing and reflecting upon the results of doing so, but I think most of the original places where 4 or more dice are used, are more or less appropriate in difficulty for what they are.


Quote:
Originally Posted by bactram1 View Post
Now that SJGames bought the rights to TFT, reviving a beloved game from my youth, we’re back to adding dice. While it’s easy enough to house-rule 4D6 to 3D6+1 and 5D6 to 3D6+2, I’d like to see something official on this. I think it’s just too much for 50% odds to change to 15.9%. I know that SJ will probably be against this, which is why I’m calling it a heresy. SJGames could have a PDF that says: If the GM wants to change the odds of very hard feats he may want to change 4D to 3D6+2, and 5D to 3D6+3. There can be tables showing the effect this would have.
And so, I similarly would NOT just house-rule all multi-die rolls as you describe, because I don't think most of the difficulty levels are incorrect. There might be a few specific cases where I think adding an extra die is too much, and prefer a -1 to -3 penalty instead, but I'd want to take those on a case by case basis.
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Old 11-24-2018, 07:02 PM   #3
Mike P.
 
Join Date: Aug 2018
Default Re: The 3D - 4D - 5D Heresy

[QUOTE=bactram1;2224161]Die rolls in TFT are based on bell curves, usually 3D6. But when the going gets tough, you don’t adjust the result of the die rolls, instead you just roll more dice. The bell curve for 4 dice is much higher than 3 dice. The average roll on 3D6 is 10.5, and an adjusted skill level of 10 will succeed 50% of the time.

A beginning 32 pt. character has an average stat (ST, DX,or IQ) of 10.67, and would actually make an ability check more than 50% of the time. Of course your adjDX might be lower, but that trade off of armor and hits stopped vs. chance of success is a big part of what makes TFT unique. Also the game is designed so that you may rapidly gain your first several attribute points, so your chances of making 3D or even 4D rolls changes fast for those attributes you choose to improve.
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Old 11-24-2018, 07:14 PM   #4
hcobb
 
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Default Re: The 3D - 4D - 5D Heresy

The game requires GMIC-ary and that means there are characters with IQ 20 who have a 77% chance of passing a five die roll. Which IQ 15 characters only have a 30% chance of.

If instead you made this a 3d roll at -8 then the IQ 20 character would have a 74% chance while the IQ 15 character would be down at 16%.

Adding dice makes for a more even playing field for the non-freaks than slapping on huge modifiers instead.
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Old 11-24-2018, 08:55 PM   #5
bactram1
 
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Default Re: The 3D - 4D - 5D Heresy

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Originally Posted by hcobb View Post
The game requires GMIC-ary and that means there are characters with IQ 20 who have a 77% chance of passing a five die roll. Which IQ 15 characters only have a 30% chance of.

If instead you made this a 3d roll at -8 then the IQ 20 character would have a 74% chance while the IQ 15 character would be down at 16%.

Adding dice makes for a more even playing field for the non-freaks than slapping on huge modifiers instead.
I'm more used to playing with lower level characters. Being able to slow down the very high point characters, while letting medium points still have a chance is good. Thanks for this.

I suppose the heresy should remain a heresy. I'll stick with the 4D6 and 5D6 rolls. Thanks.
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Old 11-29-2018, 04:19 PM   #6
ParadoxGames
 
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Default Re: The 3D - 4D - 5D Heresy

As someone who's into statistics, I too thought that rolling 4d against an attribute is a very steep difference.
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Old 11-29-2018, 04:35 PM   #7
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Default Re: The 3D - 4D - 5D Heresy

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Originally Posted by ParadoxGames View Post
As someone who's into statistics, I too thought that rolling 4d against an attribute is a very steep difference.
It's not just that more dice have a higher average roll and a greater spread. ITL higher dice rolls have greater chances of critical failures.
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Old 11-29-2018, 04:39 PM   #8
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Default Re: The 3D - 4D - 5D Heresy

Another whopping difference is that the result tends more and more toward the middle values as the number of dice increases. That's a serous change, IMO.
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Old 12-01-2018, 04:20 PM   #9
zot
 
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Default Re: The 3D - 4D - 5D Heresy

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Originally Posted by hcobb View Post
It's not just that more dice have a higher average roll and a greater spread. ITL higher dice rolls have greater chances of critical failures.
For this, we had a discussion awhile ago about rolling 3 dice of one color and extra dice of a different color, with the 3 dice determining critical/automatic success/failure (for 2 die-rolls, roll two of one color and and extra one of another and ignore the extra one if it's not critical/automatic).
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