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Old 09-10-2021, 10:28 AM   #1
GamerApe
 
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Default Extra Dice VS Negative Modifiers

When using ITL, how do you decide whether a difficult task means more dice to roll against an ability, or assign a negative modifier to a 3 die roll? There are specific cases mentioned in the rules, but what is the core reasoning? If the task itself is difficult, do you add more dice? If an untrained person would have more of a struggle, add more dice? If a trained character lacks the necessary tools, then you put on a negative modifier?
I would like to be consistent running my games, and I'd like to hear from folks how they decide a situation deserves either extra dice or a modifier. Thanks!
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Old 09-10-2021, 11:30 AM   #2
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Default Re: Extra Dice VS Negative Modifiers

My own guideline...

Adding dice has the effect of increasing the impact of random chance on the outcome... more dice means more variation. Modifiers to rolls (which are fixed values) reduce the impact of 'randomness' in either a positive or negative way.

Therefore, if you want to increase the difficulty of a task you should first ask if it is harder due to factors outside of anyone's direct control (and add extra dice) or if the outcome is more influenced by measurable factors like skills.
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Old 09-11-2021, 02:03 AM   #3
Steve Plambeck
 
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Default Re: Extra Dice VS Negative Modifiers

An interesting twist to using extra dice (as opposed to negative modifiers) is that if you couple that with the non-canonical rule of keeping those auto failure numbers of 16 and above the same, regardless of the number of dice, then you don't just make a successful roll less likely (which doesn't help much with a really high attribute anyway) but you also skew the results towards "something terrible" happening. When figures attempt something they really, really shouldn't be trying in the first place, I rather like seeing the risk of auto failure increasing as well, and at the same time the chance of a huge auto success roll literally evaporating. Plus, I've always been too dang lazy to memorize what all those different auto failure and success numbers are for different numbers of dice :)

Besides choosing between attribute modifiers and varying the number of dice, there is a third method for tweaking die rolls that, as far as I know, goes entirely unused in TFT. That is, instead of modifying the attribute being tested or the number of dice rolled for the test, modify the result of the roll itself. (We do see that in weapon damage rolls, but never anywhere else).

What's the difference between (for example) charging a -2 DX penalty on a (3d6) roll, or leaving the DX alone and making the result of the roll itself equal to (3d6)+2? The difference is that this way increases the chance of an auto failure. In this example a figure with a DX of 16 succeeds at the roll if they roll a 14 after applying a -2 DX penalty. If instead you add +2 to the amount rolled, then a 14 becomes a 16, which is an automatic miss. And if you are applying bonuses instead of penalties, a -2 to the number rolled (rather than a +2 DX bonus) increases the chances of getting a (net) roll of 3 or 4 for triple or double damage.

This provides for much more fine tuning than adding or subtracting dice, each of which has an average effect of 3.5 on a roll. Now you can leave those auto success and failure cutoffs for the different numbers of dice just as they are, while still making tiny incremental adjustments in the likelihood of automatic results. And even a figure with an enormously high DX has to think twice about attempting something very hard. All the DX in the world won't help them if they roll a 12, but the difficulty modifier was +4 to the die roll.

Besides all that, just heaping on more and more dice to make something difficult has another drawback. It ruins the beautiful bell curve we have with 3d6, a bell curve very much at the heart of the whole system. The more dice rolled, the larger the "sample size". Roll 10 dice and you'll seldom see any result other than 35. As soon as you start exceeding 3d6, you'll note a marked tendency of rolls to vary less and less often from 3.5*n, where n is the number of d6s rolled. (What's happening here is that the standard deviation falls off rapidly as you increase the sample size.) You'll seldom see a number much above or below 14 on 4d6, although it will still happen sometimes. And it gets worse rapidly as you add more dice. Variety and variability goes out the window with too many dice.
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Old 09-11-2021, 05:03 AM   #4
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Default Re: Extra Dice VS Negative Modifiers

These are very good points, that increasing dice -- as opposed to modifiers -- reduces variation and increases the rate of auto-failure.

Quote:
Originally Posted by Steve Plambeck View Post
Plus, I've always been too dang lazy to memorize what all those different auto failure and success numbers are for different numbers of dice :)
I still like, use, and will plug :) Rule of 19 thread (scroll down a few to get to the TL;DR). No tables, auto-failures increase according to RAW, and a "just read it" interpretation of critical vs regular auto-failures and successes.

Last edited by RobW; 09-11-2021 at 10:11 AM.
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Old 09-16-2021, 07:01 AM   #5
philreed
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Default Re: Extra Dice VS Negative Modifiers

Personally, I’m a fan of modifying die type to reflect difficulty. Is it just a little easier? Change from d6 to d5 or d4. Is it much harder? Change from d6 to d10.

Then roll three dice.
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Old 09-17-2021, 03:55 PM   #6
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Default Re: Extra Dice VS Negative Modifiers

Quote:
Originally Posted by philreed View Post
Personally, I’m a fan of modifying die type to reflect difficulty. Is it just a little easier? Change from d6 to d5 or d4. Is it much harder? Change from d6 to d10.

Then roll three dice.
Phil, the problem is that we have very little guidance for what die totals make for a break weapon result on 6d6 and none for 3d12.

My wild guesses from the few clues we do have are here:

https://www.hcobb.com/tft/TFT_Saving...rcentages.html

All of those D&D players who delight in rolling a 20 should consider that our 3 on a 3d6 is less than a tenth as likely.
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Old 09-18-2021, 01:54 AM   #7
Steve Plambeck
 
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Default Re: Extra Dice VS Negative Modifiers

Quote:
Originally Posted by hcobb View Post
...the problem is that we have very little guidance for what die totals make for a break weapon result on 6d6 and none for 3d12.
And that's the problem in a nutshell.

What I blabbed about in my early, overly long post can be summed up a bit more succinctly, and handled by a house rule:

Let rolling 5 or less on any number of dice always be automatic success. Let rolling 16 or more on any number of dice always be automatic failure. Then any variation from rolling 3d6 quickly and strongly skews the outcome. As the number of dice increase, automatic success becomes impossible, while automatic failure becomes increasingly frequent. (Too much auto success on 2d6 rolls though, so don't count those.)

To prevent "bunching" of results (ie, on 4 or more dice there is still only once chance of rolling exactly 16, one chance of rolling exactly 17, but many chances of rolling 18 or more, which would be undesirable) so roll one more d6 whenever an automatic failure or success occurs, and index the roll to a results table simple enough to just remember. You can fine-tune the extreme results as well. For example, on auto success roll 1 d6: 5 & 6 are auto-hit, 4 & 3 are double damage, 1 & 2 are triple damage (or tweak that all you want; in this example triple damage would be a bit more frequent than RAW). Then a similar 1d6 table for what specific auto failure occurs. You could even make these tables a bit larger and more varied with colorful, customized results of the GM's choice if you want things more complicated.
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Old 09-18-2021, 07:29 AM   #8
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Default Re: Extra Dice VS Negative Modifiers

This is where using the idea that someone offered on another thread, of three "crit" dice of a different color than the dice addied for extra difficulty, is useful; just use those to determine the extreme results and only add the other die or dice if the crit dice yield 6 through 15. The drawback is that it does not give a progression of increasing likelihood of crit failure, but it is fast and easy to remember.
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Old 09-18-2021, 09:48 AM   #9
Peter von Kleinsmid
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Default Re: Extra Dice VS Negative Modifiers

Quote:
Originally Posted by Shostak View Post
This is where using the idea that someone offered on another thread, of three "crit" dice of a different color than the dice addied for extra difficulty, is useful; just use those to determine the extreme results and only add the other die or dice if the crit dice yield 6 through 15. The drawback is that it does not give a progression of increasing likelihood of crit failure, but it is fast and easy to remember.
Yes, this is what I do if I want the same chances of a crit. If you don't have three dice of a different color from the others, you can do the same thing by just rolling three dice first to check for a crit, then add the others if not.
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Old 09-18-2021, 01:06 PM   #10
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Default Re: Extra Dice VS Negative Modifiers

RAW's handling of multidice rolls increases the risks and dilutes the rewards when more dice are added on. At 4d6 the chance for triple damage is a sixth that of 3d6. (one chance in 1296 vs one in 216). While the chance of an auto-miss or worse increases from 4.63% to 5.4%.

Hence having talents that reduce the number of dice rolled makes a critical failure much less likely. (If you get the roll down to 2d6 then you never suffer a critical failure.)
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