Well your dice could be poorly made, causing a slight deviation in random number generation. I found this out a long time back when we tracked our rolls (another player was doing a study for his statistics class), and my average (mean? median?) on my d20 was a 4. I looked it up online and found a method where you could check, and it was a bad die. It involved having it float in water and spinning it, but I honestly don't remember the details (I'm sure it's on the web somewhere).
Et tu d20?
- Thread starter Vaslov
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GMMichael
Guide of Modos
Average=mean: sum of all outcomes / number of outcomes.
Median: the outcome in the middle of the entire set.
Mode: the outcome with the highest number of occurrences.
Worse than poorly made, those dice could be sabotaged! What if all of the edges on the far side of the die from 1 were rounded/filed? That would cause the 1-side of the die to roll worse, making it stickier...
By the way Shiroiken, I'm not impressed by average roll of 4 unless you rolled that sucker a good 300 times or more. Anyone can have a bad session or two of rolling.
Possible fix: in Modos RPG (see signature) a low roll isn't a bad roll until the GM rolls higher than you. So people with an average d20 roll of, say "4," just need to utilize a different rolling system to bring their luck back up.
It was over 8 sessions of 6+ hours each, so 300 times wouldn't be out of the question, but I no longer remember the details (this was about 15 years ago).
When he told me the results, I looked online for a way to check the dice, and the method showed that my die was improperly weighted to roll "2" more frequently. It was probably either improperly weighted or milled, but either way I got rid of it. Interestingly is showed that "lucky" and "unlucky" dice exist, but are pretty rare.
My first time playing Rolemaster, my first attack roll with my first PC, I rolled open-ended negative to -483 against 1-in-3.2M odds, which led to my character biting his own head off twice.
I was later (very recently) informed that attack rolls are not supposed to go OEN in Rolemaster, and that fatally injuring myself with a bite attack should not have been possible-- but bad readings of the rules aside, it wouldn't have been possible without that colossal misfortune.
Gorgon Zee
Hero
So, a bit of statistical practice needed here. Statistical odds are calculated assuming that you declare an experiment, run that experiment, and report it. However when people report odd dice rolls, they do not do that, they are reporting an unusual chain after it has been done, so effectively they are picking the "most unusual" of a set of dice results.
This is not the easiest sort of thing to work out, so I'm going to make the slightly inaccurate simplification of saying that each chain of rolls is independent (so the odds of rolling 6 20s for the first roll of the night is independent of that for the second). This is obviously wrong, but won't affect the end probabilities by more than 10%, so I'm going for it.
d20s are rarely fair; so 3 columns in the table below for slightly bad and very bad dice. As Umbran notes, with fair dice the odds of either 6 20s or 61 in a row is about the same as winning the Texas lottery. Doing the math on rolls / decade, that would give < 0.1% chance of seeing it happen in a decade.
However with a badly unfair dice, it'll happen every second decade, on average.
This is not the easiest sort of thing to work out, so I'm going to make the slightly inaccurate simplification of saying that each chain of rolls is independent (so the odds of rolling 6 20s for the first roll of the night is independent of that for the second). This is obviously wrong, but won't affect the end probabilities by more than 10%, so I'm going for it.
d20s are rarely fair; so 3 columns in the table below for slightly bad and very bad dice. As Umbran notes, with fair dice the odds of either 6 20s or 61 in a row is about the same as winning the Texas lottery. Doing the math on rolls / decade, that would give < 0.1% chance of seeing it happen in a decade.
However with a badly unfair dice, it'll happen every second decade, on average.
Undrave
Legend
I have this super old set of dice I've had for like 20 years. First set I bought for a RPG and they have a funky distribution of number (aside form the D6, none of them have the usual "opposite sides add up to the same number" arrangement (though they're not in sequence either like a M:TG life dice) but they've been consistently well balanced.
In an AL game last year I got a Whip of Alarm that prevented me from being surprised and gave me Advantage on initiative rolls... I never rolled above a 7 on initiative after I got it ><
In an AL game last year I got a Whip of Alarm that prevented me from being surprised and gave me Advantage on initiative rolls... I never rolled above a 7 on initiative after I got it ><
