You don't need a Tengwar to succeed against Thing of Terror. You need a Tengwar to stop rolling every round for it, which is differentIndur Dawndeath wrote:I must say that your number are wrong. You have not taken into account that you need to score a Tengwar to succeed.

And, by the way, zedturtle's results are exactly the same as the ones I posted...

No, I understand the equation well, I meant that I wasn't able to understand your method.HS wrote:I'm not sure a binomial equation is any more reliable than my getting close and fudging it a bit. How were you accounting for the Gandalf rune? Obviously rolling a G rune and a tengwar is an auto success but rolling a G rune and no Tengwar is not a success. How are you accounting for that result? Rolling an Eye means no possibility of success even with two 6s on the success dice.
Are you saying that you plugged the numbers in to an equation without understanding how the equation deals with the numbers?
By the way, the calculations I made are the following:
The probability distribution of the results of 2 dices is:
2: 2,78%
3: 5,56%
4: 8,33%
5: 11,11%
6: 13,89%
7: 16,67%
8: 13,89%
9: 11,11%
10: 8,33%
11: 5,56%
12: 2,78%
The Action dice (D12) is taken into account by saying: how do I reach, say, TN 18 with every one of the probabilities shown above by adding to them the roll of a D12?
Well, with results from 2 (2.78%) to 7 (16.67%), your only possibility is to roll a Gandalf (automatic success), which is 8.33% (1/12). With a result of 8, you have to roll Gandalf or 10 (16.67%, or 2/12). With a result of 9, you have to roll G, 10, or 9 (25%, or 3/12)... and so on.
So the probability of obtaining 18 is P = 8.33% x (2.78% + 5.56% + 8.33% + 11.11% +13.89% + 16.67%) + 16.67% x (13.89%) + 25% x (11.11%) + ... = 16.44%
So you don't need to think about the mean values (Gandalf results cannot be taken into account to calculate mean values), you just use the probabilities of success, which are perfectly accurate.
Put this in a spreadsheet and you can quickly calculate the probability of success for every TN, and for every number of dices.
It sounded more rough as I intended it to be, and I'm sorry for that. So thanks for your understanding, I really didn't want to offend and I'm glad this wasn't the case.HS wrote:BTW I wasn't offended by your abruptness as I recognise that English is not many peoples first language here and make allowances for incorrect or uncertain phrasing.