Boon/Bane Dice Probabilities

[Wizard]

I believe that the Boon/Bane mechanic has a definite place in Traveller. There are 2 reasons, first one is that I think it is a fun mechanic, ie, rolling more dice and picking the 2 highest/lowest is just plain fun. The other reason is that it modifies the 2d6 probability in a way DMs don't.

The current ‘hard-wired’ concept on page 61 just does not seem right to me. Just because a DM is written down in a rulebook should not determine between using a DM or Boon/Bane. I would rather see the actual impact of the situational factor itself on the Task to be what determines between using a DM or Boon/Bane.

To get a better understanding of the Boon/Bane mechanic I sat down this morning and analysed it. I have summarised what I have found together with my thoughts below.

Probabilities of rolling a value:

  0     1     2     3     4     5     6     7     8     9    10    11    12    13    14
----  ----  ----  ----  ----  ----  ----  ----  ----  ----  ----  ----  ----  ----  ----
 ...   ...  33.0% 28.8% 20.2% 10.1%  5.1%  1.8%  0.7%  0.2%  0.1%  0.0%  0.0%  ...   ...   Bane x5
 ...   ...  26.3% 27.0% 21.6% 12.8%  7.2%  3.1%  1.4%  0.4%  0.1%  0.0%  0.0%  ...   ...   Bane x4
 ...   ...  19.6% 23.7% 21.8% 15.4% 10.0%  5.2%  2.7%  1.0%  0.4%  0.1%  0.0%  ...   ...   Bane x3
 ...   ...  13.2% 18.8% 20.1% 17.3% 13.2%  8.3%  5.0%  2.5%  1.2%  0.3%  0.1%  ...   ...   Bane x2
 ...   ...   7.4% 12.5% 15.7% 16.7% 15.7% 12.5%  8.8%  5.6%  3.2%  1.4%  0.5%  ...   ...   Bane
 
 2.8%  5.6%  8.3% 11.1% 13.9% 16.7% 13.9% 11.1%  8.3%  5.6%  2.8%  ...   ...   ...   ...   2d6 DM-2
 ...   ...   2.8%  5.6%  8.3% 11.1% 13.9% 16.7% 13.9% 11.1%  8.3%  5.6%  2.8%  ...   ...   2d6 DM+0
 ...   ...   ...   ...   2.8%  5.6%  8.3% 11.1% 13.9% 16.7% 13.9% 11.1%  8.3%  5.6%  2.8%  2d6 DM+2
 
 ...   ...   0.5%  1.4%  3.2%  5.6%  8.8% 12.5% 15.7% 16.7% 15.7% 12.5%  7.4%  ...   ...   Boon
 ...   ...   0.1%  0.3%  1.2%  2.5%  5.0%  8.3% 13.9% 17.3% 20.1% 18.8% 13.2%  ...   ...   Boon x2
 ...   ...   0.0%  0.1%  0.4%  1.0%  2.7%  5.2% 10.0% 15.4% 21.8% 23.7% 19.6%  ...   ...   Boon x3
 ...   ...   0.0%  0.0%  0.1%  0.4%  1.4%  3.1%  7.2% 12.8% 21.6% 27.0% 26.3%  ...   ...   Boon x4
 ...   ...   0.0%  0.0%  0.1%  0.2%  0.7%  1.8%  5.1% 10.0% 20.2% 28.8% 33.0%  ...   ...   Boon x5

AnyDice was used to get the result (as suggested by -Daniel-). The following links have all the results from above. Click the Graph button to get a graphical representation.
http://anydice.com/program/6d1a
http://anydice.com/program/6d1b
http://anydice.com/program/6d1c

The above results show that while a DM shifts the results, a Boon/Bane reduces the effective range of the results and skews it towards one end. Having multiple Boons/Banes amplifies this effect. For example the effective range of Bane x5 (ie, roll 7 dice, keep the 2 highest) is between 2 and 6.

Probabilities of getting a certain result or higher:

   4+      8+      12+
 -----   -----   -----
 31.8%    0.9%    0.0%    Bane x5
 46.7%    2.0%    0.0%    Bane x4
 56.7%    4.2%    0.0%    Bane x3
 68.0%    9.0%    0.1%    Bane x2
 80.1%   19.4%    0.5%    Bane
 
 41.7%    2.8%     ...    2d6 DM-4
 72.2%   16.7%     ...    2d6 DM-2
 91.7%   41.7%    2.8%    2d6 DM+0
100.0%   72.2%   16.7%    2d6 DM+2
100.0%   91.7%   41.7%    2d6 DM+4
 
 98.2%   68.1%    7.4%    Boon
 99.6%   82.6%   13.2%    Boon x2
 99.9%   90.6%   19.6%    Boon x3
 99.9%   94.9%   26.3%    Boon x4
100.0%   97.2%   33.0%    Boon x5

One of the dynamics of rolling 2d6 is that as soon as the DM becomes too large/small the chance of success/failure becomes automatic and what you are rolling for is purely the magnitude of the Effect. Boon/Bane skews the results towards the extreme value of the Effect rather than changing the maximum value possible. So I would like to suggest the following to guide between using a DM or a Boon/Bane:

To increase/reduce the chance of success/failure, without changing how good/bad you perform the task, use Boon/Bane, otherwise use DMs.

With the above clause we would need examples to clarify it, such as (note I just quickly wrote these down as examples without too much thought at the moment):

• 
  DM: rush or take your time on a task, range to target, etc.
  Boon/Bane: raining, sun in your eyes, poor lighting, drunk, tool quality, etc.

I would also suggest that Boon/Bane is made stackable. I believe that the results in the tables above show that there is no real reason to be limited to just one Boon/Bane. I would think that if we start to see more than 3x Boon/Bane being rolled regularly we might have to re-assess and limit where they are being used. But the occasional 5x Boon/Bane should be possible in the right situation. Removing the limit of just one Boon/Bane also removes the need to limit when Boon/Bane is applied in the written rules.

I believe that for the Boon/Bane mechanic to be successful it needs to clearly, and for reasons grounded in reality, dictate when it should be used over a DM. Otherwise we might as well go back to the simplicity of just using DMs.

 

[ShawnDriscoll]

I believe that for the Boon/Bane mechanic to be successful it needs to clearly, and for reasons grounded in reality, dictate when it should be used over a DM. Otherwise we might as well go back to the simplicity of just using DMs.

All or nothing again.

I like the idea of experienced referees using Boon/Bane rolls to make tasks more interesting for players who narrate their actions. Role-players enjoy some uncertainty and interesting outcomes from time to time. If that means role-players then won't narrate their actions, well it just means they weren't role-players to begin with.

 

[Wizard]

I believe that for the Boon/Bane mechanic to be successful it needs to clearly, and for reasons grounded in reality, dictate when it should be used over a DM. Otherwise we might as well go back to the simplicity of just using DMs.

All or nothing again.

I like the idea of experienced referees using Boon/Bane rolls to make tasks more interesting for players who narrate their actions. Role-players enjoy some uncertainty and interesting outcomes from time to time. If that means role-players then won't narrate their actions, well it just means they weren't role-players to begin with.

Nope, I prefer logic and consistency over chaos. I have played in games where game masters use the chaos theory, just making things up on the fly with no concern about consistency. Not fun.

It also seems like you don't agree with the rules since what you are suggesting is not how the rules on page 59 or in the sidebar on page 61 are written. There is no mention of narration or role-playing in concern to Boon/Bane. They specifically mention tools, dimly lit environment, making a phone call upside down. And specifically the wording for DMs is: In general, these should be regarded as being ‘hard-wired’ into the rules, and only applied if they are listed in a Traveller rulebook or supplement.

Since we are testing the rules as written during the playtest I am sticking to them as best as I can. I believe there is an issue with Boon/Bane and trying to address it. In the end I want rules that offer as much guidance as possible as I believe that it will help new and old gamers play and enjoy the game.

 

[TrippyHippy]

I like the idea of experienced referees using Boon/Bane rolls to make tasks more interesting for players who narrate their actions. Role-players enjoy some uncertainty and interesting outcomes from time to time. If that means role-players then won't narrate their actions, well it just means they weren't role-players to begin with.

I don't think there are many on this site that don't have some experience as a referee. I myself have been roleplaying for about 30 years, and have been refereeing Mongoose's Traveller since it's inception. You don't speak for all roleplayers, experienced or otherwise, and your argument is essentially insulting as well as a non sequitur.