Dice math.

[Harlock]

Olgar, that's pretty damn funny.

 

[MerakSpielman]

IIRC, the best "gamblers" are the ones who study probability, not those who trust to luck.

 

[Saeviomagy]

IIRC, the best "gamblers" are the ones who study probability, not those who trust to luck.

But people who really know probability take one look at the odds in unfriendly games of chance and give up, knowing they are highly unlikely to win. They're not gambling.

 

[babomb]

You've flipped a coin 19 times, and each time it has come up Heads. What would you bet is the result of the 20th flip?

Have you ever read <i>Rosencrantz and Guildenstern Are Dead</i>?

 

[MerakSpielman]

That's why they play poker or blackjack. Even after figuring all the odds, choosing exactly the right times to draw or stay, the house still will win slightly more than 50% of the time in a prolonged game. The best you can do is minimize your chances of losing, bet high, and then get the hell out of there, no matter what happened. If you won, you need to leave before the odds catch up with you. You can't trust that you'll keep winning. If you lost, well, what did you expect, really?

 

[MerakSpielman]

Have you ever read Rosencrantz and Guildenstern Are Dead?

That play is just great. You have to read Hamlet first, or you won't get all the jokes, though.

The scene babomb is talking about happens at the very beginning, where Rosencrantz and Guildenstern are playing a game. They combine the contents of their money-pouches (assuming they were near equal at the start), and then flip each coin. Heads, Rosen gets the coin. Tails, Guilden gets it. (or vice versa. whatever) Generally, they don't win or lose more than a couple coins after going through the whole pouch. It's just a way of passing the time.

When they do it in the play, one of them (I forget which) is winning all the coins. The other guy is flipping, so there's no cheating, but it happens over. and over. and over. Heads, every single flip.

It's funnier if you read it yourself...

 

[Staffan]

Well... of course that dice have no memory and that knowing the average of 1d20 is no good...

Still, we have the fabulous Central Limit Theorem, thanks to which the most dice we roll, the closest the expected result (the average) matches what we actually roll... that is: Roll 10d6 and see how closely you match the average (35) each time. Roll 20d6 repeatedly and you should see that most times you're even closer to the average (70) than before.

That's not entirely true. It's true in relative terms, but not in absolute. That is, if you're rolling 20d6 you're more likely to roll outside, say, 5 points of the average than if rolling 10d6. However, you're more likely to roll inside 10 points of the average (1/10th of the span) with 20d6 than you are rolling inside 5 points of the average (also 1/10th of the span) with 10d6.

 

[Tom]

It isn't really that much use however, since dice don't have memory of what they last rolled or any knowledge of statistics and so it's entirely possible (however unlikely) for your D20 to roll 1 all its life (which no doubt would be very short as you are likely to microwave it or slam it in a vice as an example to your other dice to buck their ideas up).

It's nice to know what the average damage should be when you roll a lot of dice, because the more dice you roll, the better the probability it will end up average. So before I throw a 10th level Fireball, I'll know the damage should be around 35, not around 60 like I would get if extremely lucky. It helps me know the risk/reward of throwing the Fball (loose a action and 3rd level spell slot/inflict around 35 HPs of damage).

 

[Fieari]

Here's a puzzle that I labored over quite a while ago and gave up on, but maybe someone here can solve?

Using only multiples of a single type of die per element (xd1, xd2, xd3, xd6, xd8, xd10, xd20, (optional xd30), xd100) and +/- modifiers, construct a set where the average roll begins at n<-[0,6] and increases linearlly to infinity, while the maximum possible roll increases at a greater rate.

That means increasing the number or value of dice over time and not just picking 1d4+1, 1d4+2, 1d4+3, ..., 1d4+n

I'm sure the value of such a set would be obvious to roleplayers (and rollplayers alike)

 

[Dirigible]

While I like to think of myself as a fairly intelligent, rational man, I gotta say that when the dice start rolling badly, I swap 'em for some freshies.