Random Difficulty?

[Sister Machine Gun]

I'm really enjoying reading the OVA book. It is really simple so far and smooth to digest. I may have a few question later.

I liked how D6 Star Wars had a random way to determine Difficulty ratings. Could I use the following without hurting any thing?

Roll 2D6 added together:
1=Easy
2-3= Moderate
4-5=Challenging
6-7=Difficult
8-9=Very Difficult
10-11=Extremely Difficult
12=Nigh Impossible

Would I need to change or add any rules?

[Father of Dragons]

I liked how D6 Star Wars had a random way to determine Difficulty ratings. Could I use the following without hurting any thing?

Roll 2D6 added together:
1=Easy
2-3= Moderate
4-5=Challenging
6-7=Difficult
8-9=Very Difficult
10-11=Extremely Difficult
12=Nigh Impossible

Would I need to change or add any rules?

I wouldn't think there would be any rule issues. However, one of the things I like about OVA is the general assumption of competence for the characters -- even a character with no specific advantages gets two dice to try an action. However, a lot of your more common difficulties (Difficult and Very Difficult will be the most common, with 11/36 and 1/4 chances respectively (and Easy (EZ) is impossible, since the minimum total is 2)) are not that easy for two dice to achieve. Here's the success chance for two dice:

Code: Select all

#D    EZ ( 2)   MO ( 4)   CG ( 6)   DF ( 8)   VD (10)   ED (12)   NI (15)
=========================================================================
 2    97.222%   80.556%   38.889%    8.333%    5.556%    2.778%    0.000%

(From my post on success chances here.) Notice how small the chances of success for Difficult (DF) and Very Difficult ((VD) are for a character without an applicable advantage? In a world where difficulties are assigned using that table, characters are generally not very competent, which I think would lose one of OVA's more attractive features.

Mind you, if the table used OVA dice pool rules for two dice instead of simply adding the two dice, it wouldn't be quite so brutal (although Easy difficulties still wouldn't come up enough).

[Sister Machine Gun]

I'll take your world for it Father of Dragons. Thank you for explaining that, but most of it went over my head since I ain't that profecient in math. Ok that's out then.

I goofed in distributing the totals wrong. There's no 1 in 2D6 added together.

[Father of Dragons]

I'll take your world for it Father of Dragons. Thank you for explaining that, but most of it went over my head since I ain't that profecient in math. Ok that's out then.

The idea was sound, the problem was with the execution. An easier table would be just fine. Maybe:

Roll 2D6 added together:
2-5 = Easy
6-7 = Moderate
8 = Challenging
9 = Difficult
10 = Very Difficult
11 = Extremely Difficult
12 = Nigh Impossible

Would be better.

[wuxiasnake]

Remember 2d6 is a bell type probability curve, not linear.

That is to say for, example, that there are 6 different combinations of numbers that add up to the total of 7 (1+6,2+5,3+4,4+3,5+2,6+1) but only one combination which adds up to 2 (1+1).

Its essential to consider this if you're going to use this method.Here is a link to an in depth article on 2d6 probabilities. http://www.tauonline.org/Article/121/Si ... abilities/

[Joe_Mello]

Perhaps I'm oversimplifying this, but if you want random difficulty, why don't you just make the situation an "opposed roll"?

[Clay]

I think Joe has the right idea.

In Ironclaw by Sanguine Publishing, all difficulties are represented by random dice rolls of varying sizes. An easy task may be 1d4 and a difficult task something like 2d12. (My memory is fuzzy here)

Creating a chart with various number of dice would be an okay solution to me.

If you were really sold on the chart idea, you should take into account the bell curve Snake pointed out. Probably something more like this:

12 - Nigh Impossible
2 or 11 - Extremely Difficult
3 or 10 - Very Difficult
4 or 9 - Difficult
5 or 8 - Challenging
6 or 7 - Moderate

Easy can be left off the list. After all, it's basically an automatic success anyway.