Sick Odds

I like to play the Pandemic cooperative board game series (for which I just learned there is now a third expansion, along with the non-cooperative tie-in game where you play as diseases trying to wipe out mankind). Awhile ago received a present of the dice version, called Pandemic: The Cure, so on my birthday I got to choose a game to play, and that's what I picked. We'd only played it once before that, and I was surprised when we lost badly three times in a row. Only one of those times were we even close.

While our strategy was certainly suboptimal, the real culprit, I believe, was the number of players. Three seems to be perfect for most of the board game variants, with other numbers of players (both higher and lower) possible but tricky. For The Cure, though, I suspect more is always better. The game is listed as 2-5 players, but it seemed that three was too few. When we played the first time out of the box, we went ahead and used all seven characters since that was the number of people we had present, and the game was simple to beat. We will have to play some more and see if the number of players really makes that much of a difference, or if we just had a bad night of poor strategy. (The link above suggests that other people disagree and think 3-4 is probably best, and that the game can swing between simple and brutal on just a few dice rolls.)

The thing that stuck out to me, though, was the dice themselves. Each color (representing a different disease) has a different set of numbers on its faces. For example, black has three 3s, and one each of 0, 4, and 5. Compare that to blue, which has one each of 0, 1, 2, 3, and 4, plus two 6s. Since you roll the disease cubes individually to see where they end up, this ensures that the different colors show up preferentially on different continents (numbered 1-6, plus 0 for no effect). But since you also roll multiple dice of a given color together to try to "find a cure," it also impacts the odds of rolling the required sum (usually 13).

I was going to do the math to figure out the probabilities, but a quick web search reveals that other geeks have already done this. The upshot is that with 4 or more dice the colors behave nearly the same: all have a 45% chance of success with 4 dice, 5 dice takes you up to between 67% (red & blue), and 77% (black), and 6+ gets you into 90% territory. But if you are trying with only 3 dice, you'd better be using the scientist (who only needs a sum of 11) because she has about a 1 in 3 chance with all colors. Everybody else needs to pay attention to the color, because they are very different from each other. With three dice, your chances of success are: 23% (blue), 20% (red), 12% (yellow), and 7% (black).