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Pen & Paper Roleplaying Central => Pen and Paper Roleplaying Games (RPGs) Discussion => Topic started by: Bagpuss on February 28, 2006, 08:16:24 pm

Title: L5R - Dice
Post by: Bagpuss on February 28, 2006, 08:16:24 pm
Just what is the probability on a system where you roll X number of D10's keep Y number of them, and any natural 10's explode? It's making my head hurt just thinking about it.
Title: L5R - Dice
Post by: Bagpuss on March 01, 2006, 06:42:46 am
Can someone at least work out the mean on an exploding D10.

IE: if it rolls a 10 you roll again and add.
Title: L5R - Dice
Post by: Chacal on March 01, 2006, 10:39:39 am
open ended (high) D10 I'd say  about 6.1 (which is roughly about 5.5 +5.5/10 )
if it's open ended (low) it changes a little bit, though ...

I'm not sure I understood the first question. You stated the system, but not the event you want to know the probability of :confused:
Not that I can actually answer it, my statistics are way too much rusted at this point :D

Chacal
Title: L5R - Dice
Post by: obryn on March 01, 2006, 11:35:39 am
Quote from: Bagpuss
Just what is the probability on a system where you roll X number of D10's keep Y number of them, and any natural 10's explode? It's making my head hurt just thinking about it.

I thought - but could easily be wrong - that any exploding die averages out to basically .5 over the mean.

So, an exploding d6 has a mean of 4.  An exploding d8 has a mean of 5.

The fact that this matches Earthdawn's step numbers is no coincidence. :)

-O
Title: L5R - Dice
Post by: Chacal on March 01, 2006, 11:50:44 am
Quote from: obryn

The fact that this matches Earthdawn's step numbers is no coincidence. :)
-O

:eek:  You said "Earthdawn" in a thread about statistics. I must wash my brain now !:D


Chacal
Title: L5R - Dice
Post by: Bagpuss on March 01, 2006, 01:39:18 pm
I wanted to know how to calculate the expected mean of whole load of dice combinations.

2k2
3k2
4k2
5k2
6k2
7k2

3k3
4k3
5k3
6k3
7k3
8k3

4k4
5k4
6k4
7k4
8k4
9k4

for example where you roll XkY dice X is the total number of exploding D10's you roll and Y is the number you keep the values off and add together to get the result.

So 1k1 is going to be 6.1, 2k2 is going to be 12.2, but how do you work out the values for the ones where you can discard the low rollers.
Title: L5R - Dice
Post by: Chacal on March 02, 2006, 06:18:49 am
Interesting...
Lazy as I am, I tried google and wikipedia, but couldn't find an entry for these kind of questions. It's strange because they're asked for quite frequently on messageboards.


Chacal
Title: L5R - Dice
Post by: Bagpuss on March 02, 2006, 06:22:41 am
Think I've found it...

http://www.umsl.edu/~ccb555/L5ROdds.xls

And this thread at AEG

http://www.alderac.com/forum/viewtopic.php?t=13206
Title: L5R - Dice
Post by: Chacal on March 02, 2006, 06:32:04 am
Nice ! Thanks !
(you'd get rep if I could give it)

Chacal
Title: L5R - Dice
Post by: Bagpuss on March 02, 2006, 01:54:30 pm
I've been doing some playing around with the data for those links.

Assuming Attributes start at 2 and skills at 0. So obviously favouring clan/school attributes and school skills will make this slightly off.

It looks like the only way to get an average over 30 is to have Keep 4, or Keep 3 and a skill of 6+. Cheapest way is 4 in the attribute and 2 in the skill.

So if it wasn't for Mastery bonuses and Emphases it would always be best to raise attributes to 4 before raising skills much past 2. Although it's very hard to make fair comparisons with Mastery, Emphases and school/family bonuses.

I think we might have discovered a game its very hard to min-max.....

Well except for some of the stupid advantages.
Title: L5R - Dice
Post by: Dacke on March 02, 2006, 02:07:23 pm
Quote from: Bagpuss
Can someone at least work out the mean on an exploding D10.

IE: if it rolls a 10 you roll again and add.

Exploding die, I can do. I think. With A being the average result on the die:

A = (1+2+3+4+5+6+7+8+9+(10+A))/10 = (55+A)/10 = 5.5 + 0.1*A
0.9*A = 5.5
A = 5.5/0.9 = 6.11
Title: L5R - Dice
Post by: Bagpuss on March 02, 2006, 03:25:19 pm
This useful? Chance of hitting TN's going up in 5's, based on rolling 3k2 to 10k5 dice. I've removed any TN that was less than 10% chance to keep it to two pages.

What it clearly shows is 5k3 is better than 7k2. Buying a attribute from 2 to 3 is 12 CP's and buying a skill from 2 to 5 is also 12 CP's. So unless you have Emphases or gain a really good mastery from level 5 it's better to improve the attribute.
Title: L5R - Dice
Post by: Chacal on March 08, 2006, 02:50:52 am
I don't play L5R and still find it useful :o

Chacal