Dice Calculator

[clmckay]

I don't know if anyone is interested in this, but I made a simple spreadsheet to calculate certain probabilities for the colored dice. I had thought there was one around here somewhere but couldn't find it so just made my own.

Probability-Revised.xlsx

[Maurice76]

There is one:

Dice probability sheet, made by me. It will accept any combination of dice (up to 10) of either HeroQuest or Space Crusade and show you the chance distribution across the possible outcomes. With ease you can even add new dice distributions easily.

[clmckay]

No, I haven't seen yours before. I'm pretty sure Count Mohawk had made one once. In fact I think I had played with his to add some combinations in a few years back but misfiled it. In any event it's a moot point, this is here for any who want it. You can make custom combinations by simply plugging numbers in and exploring the output.

[Anderas]

It gets interesting when you add rerolls. Like.

Roll 3 white and a black. You may reroll one walrus.

[clmckay]

Well....I lack the technical ability and drive to add rerolls for Black Shields, but I did like the idea of mixed dice scoring, even though I seldom use them that way. So I added it to the OP.

[Maurice76]

The problem with rerolls is that they can mount up, so to speak. Suppose you roll 5 dice and on the first roll, you get



Then you reroll both blackies:



Reroll the blacky:



Reroll the blacky again:



End result:



The problem is that programatically, there's a very small but non-zero chance that you keep rolling 's on every die, with every roll. The only way to remedy this would be to allow the user to specify the maximum number of rerolls.

[cornixt]

Not really. If Black shields are always rerolled, you just ignore the possibility of rolling it, so it's a 3/5 chance for skulls and 2/5 for white shields.

[Anderas]

Yes, reroll eternally would be easy. Reroll once, too.
My example was meant to be even simpler: Fixed number of dice to reroll, and reroll only once.

Here it comes:
Reroll if you like, but if yes then reroll all, you must accept the second result. That's difficult. If you have a Skull, do you reroll, risking to lose it or not? Simulating the decision is where it becomes difficult.

[benvoliothefirst]

I thought it was a pretty universal rule that you can only re-roll a die once. "You can't double stamp a triple stamp!" etc.

[Maurice76]

I thought it was a pretty universal rule that you can only re-roll a die once. "You can't double stamp a triple stamp!" etc.

Hm, good point. I was looking at it from a mathematical point of view too much, I guess .

Still, if you reroll only once, you can still get another . So your initial roll and your reroll have different odds, if you combine them in one. Basically, you have to split up all 's into sub-odds of each of the possible symbols. Shouldn't be too hard to implement.