Warhammer Fantasy Magic - chance of successful spell casting, miscasts & irresistable force

The best number of power dice to use when casting spells

Number of dice
Casting value12345Suggested # of dice
3+ 66.7%97.2% 92.6% 86.8% 80.4% 2
4+ 50.0% 91.7% 92.6% 86.8% 80.4% 2
5+ 33.3% 83.3% 92.6% 86.8% 80.4% 3
6+ 16.7% 72.2% 91.2% 86.8% 80.4% 3
7+ 0 58.3% 88.0% 86.8% 80.4% 3
8+ 0 41.7% 82.4% 86.8% 80.4% 4
9+ 0 27.8% 74.1% 85.5% 80.4% 4
10+ 0 16.7% 62.5% 83.3% 80.0% 4
11+ 0 8.3% 50.0% 79.5% 80.0% 4
12+ 0 2.8% 37.5% 73.3% 79.3% 5
13+ 0 0 25.9% 65.0% 77.9% 5
14+ 0 0 16.2% 52.5% 75.2% 5
15+ 0 0 9.3% 44.4% 71.0% 5
Average* 3.5 7.0 10.5 14.0 17.5
I. Force **0 2.8% 7.4% 12.7% 17.7%
Miscast *** 0 2.8% 7.4% 13.2% 19.6%

* Average - average total dice score when you roll that number of dice, eg. rolling 2 dice gives an average score of 7
** I.Force - the likelihood that you will cast a spell with Irresistable Force
*** Miscast - the likelihood that you will miscast a spell if you roll the given number of dice.

How to use this table :-

The percentages in the center of the table show the chance you have of successfully casting a spell given the number of dice you are rolling and the casting value of the spell.

Suggested # of dice is the best number of dice to use to maximise your chances of success.

* Note that a miscast always overrules a spell cast with irresistable force. So if you roll 4 dice and 2 are 1's and 2 are 6's then the spell is miscast. This is why, when you roll 4 or more dice, there is more chance of a miscast than irresistable force.


source: folk.ntnu.no/tarjeia/avian/calculations/casting.php
(thanks to warphammer.wordpress.com who discovered this resource)