Wednesday, February 11, 2009

Information Highway: Crypt Probabilities

These are the basic probabilities for drawing at least one copy of a vampire in your starting crypt (of 4) given a number of that vampires in a crypt of 12:
  • 1 copy in a crypt of 12 -- 33.33%
  • 2 copies in a crypt of 12 -- 57.58%
  • 3 copies in a crypt of 12 -- 74.55%
  • 4 copies in a crypt of 12 -- 85.86%
  • 5 copies in a crypt of 12 -- 92.93%
  • 6 copies in a crypt of 12 -- 96.97%

3 comments:

Anonymous said...

What about the possibility of drawing *only* Arika when packing 4,5 or 6 of her? :)

extrala said...

The probability to get exactly 4 copies of the same vampire in your starting crypt when your crypt of 12 contains X copies of the same vampire:
4 copies -- 0,20%
5 copies -- 1,01%
6 copies -- 3,03%
7 copies -- 7,07%
8 copies -- 14,14%
9 copies -- 25,45%
10 copies -- 42,42%
11 copies -- 66,67%
12 copies -- 100,00%
It's kind of the reverse of the initial question. Imagine how great are the chances of not-getting at least one non-Arika in the starting crypt, when having 1 to 8 copies of non-Arikas in starting crypt of 12.

extrala said...

The actual probabilities to get exactly 4 copies of the same vampires do not look that bad, but have look at this:

The probability to get 3 or 4 copies of the same vampire in your starting crypt when your crypt of 12 contains X copies of the same vampire:
4 copies -- 6,67%
5 copies -- 15,15%
6 copies -- 27,27%
7 copies -- 42,42%
8 copies -- 59,39%
9 copies -- 76,36%
10 copies -- 90,91%
11 copies -- 100,00%
This is bad, having 6 copies of the same vampire gives you a chance of ~27% to get none or one other vampire than your star vampire.