[Dice!]Spindowns vs. Normal d20s

[arguskos]

Is there any difference between spindowns and normal d20s, as far as randomness goes? I'm superstitious about these things, and want to know what science can tell me.

[herrhauptmann]

What's a spindown dice?

[sofawall]

Is there any difference between spindowns and normal d20s, as far as randomness goes? I'm superstitious about these things, and want to know what science can tell me.

There's a dice thread, if anyone wants to find it. The dude there is pretty knowledgeable.

[GoodbyeSoberDay]

On a real roll with fair dice, there is no significant difference. That said, the spindown dice can be weighted towards the higher numbers more easily, and particularly clever cheaters can learn to "roll" an ostensibly fair spindown dice towards the higher end.

[Flickerdart]

Well, the main difference is that a regulation d20 has the high and low numbers evenly distributed, and a spindown die has all the big ones on one side. If your die has a rolling bias, it's going to be a lot more pronounced with the spindown, which aren't made to be rolled anyway and are more likely to be deformed (and have a bigger bias).

[arguskos]

What's a spindown dice?

A spindown is a die that looks as such:

See how the numbers move down in descending order (the symbol is a 20)? It's so you can "spin the die down" in games and such.

EDIT: That's what I was afraid of. I've been considering using a few in a game for a bit, simply to test them out (I've got one or two I really love the look of). I'll probably report back on Monday on their performance, if anyone's interested.

[Sstoopidtallkid]

EDIT: That's what I was afraid of. I've been considering using a few in a game for a bit, simply to test them out (I've got one or two I really love the look of). I'll probably report back on Monday on their performance, if anyone's interested.

Your dice already try to slaughter us. This has me worried.

[Grynning]

A spindown is a die that looks as such:

See how the numbers move down in descending order (the symbol is a 20)? It's so you can "spin the die down" in games and such.

EDIT: That's what I was afraid of. I've been considering using a few in a game for a bit, simply to test them out (I've got one or two I really love the look of). I'll probably report back on Monday on their performance, if anyone's interested.

To clarify, these dice are generally made for keeping track of score/life totals in CCG's, Magic the Gathering particularly. Originally people just used regular d20's for this, but it was a bit cumbersome as you had to hunt for the numbers each time the total changed. A spindown die makes it easier to go up/down a scale of 1-20. They're not meant to be rolled.

[arguskos]

Your dice already try to slaughter us. This has me worried.

I'm trying out new ones! I have roughly 15-20 d20s, not all of them can slaughter you, amirite?

[Kylarra]

I'm trying out new ones! I have roughly 15-20 d20s, not all of them can slaughter you, amirite?

I dunno. Our DM changes dice often and they always seem to crit when he needs them regardless...

[arguskos]

I dunno. Our DM changes dice often and they always seem to crit when he needs them regardless...

I have no less than THREE dice called The Player Killer (@Sstoopid, I'm referencing the orange one, the blue metallic one, and the purple transparent one).

I've been trying to find one that doesn't really slaughter my players. So far, I'm having mixed results. >_>

[PairO'Dice Lost]

I dunno. Our DM changes dice often and they always seem to crit when he needs them regardless...

I have one die that, for the two full campaigns I've DMed with it, has rolled nothing but 19s and 20s when I rolled for enemies and 1s and 2s when I've rolled for players (hidden skill checks, etc.). I am no longer allowed to use it for anything except the BBEG fight.

[Sstoopidtallkid]

I've been trying to find one that doesn't really slaughter my players. So far, I'm having mixed results. >_>

To put this in perspective, at our session last week, Arguskos rolled hidden spot checks for our group, all 5 of us. None of us have invested in it(just lost the char that did), but the DC was only 15. 3 monsters, 5 checks per monster. We failed all of them. Assuming a +0 to the check(which I know a couple of us were better than), that was a 00.47% chance of happening.

His dice are EBIL!!!1!

[arguskos]

To put this in perspective, at our session last week, Arguskos rolled hidden spot checks for our group, all 5 of us. None of us have invested in it(just lost the char that did), but the DC was only 15. 3 monsters, 5 checks per monster. We failed all of them. Assuming a +0 to the check(which I know a couple of us were better than), that was a 00.47% chance of happening.

His dice are EBIL!!!1!

Oh, and let me add something: I changed all five dice each time I rolled, thinking that everyone failing was strange. >_> Didn't matter at all.

So, yes, time to try spindowns. Maybe they won't fail so hard.

[GoodbyeSoberDay]

To clarify, these dice are generally made for keeping track of score/life totals in CCG's, Magic the Gathering particularly. Originally people just used regular d20's for this, but it was a bit cumbersome as you had to hunt for the numbers each time the total changed. A spindown die makes it easier to go up/down a scale of 1-20. They're not meant to be rolled.

Generally I see people use two different-colored d10s for this purpose.

[arguskos]

Generally I see people use two different-colored d10s for this purpose.

Spindowns only come in fat packs, making them somewhat tricky to acquire at times.

[nyjastul69]

I've also heard them called spin down dice. I've never experienced a situation where I thought a player was cheating with said dice but it is possible.

My understanding is that the platonic solids should have opposite faces equal to n+1, n= # of faces. A d6's opposite sides should add up to 7, etc. I don't where the d10 falls in that regard as it's not platonic. I don't know if there's a statistical difference.

That said, there are tests one can put their dice through to check for a bias. The only one I've ever used was a chi-squared test printed a Dragon Mag from the late 70's or early 80's (issue #'s, not years).

I really wouldn't worry about it unless the player 'looks' like he/she is cheating.



Edit: The oddest thing I've ever experienced with spindowns is WotC including them in the starter sets for the DDM game and then not allowing those same dice in tournament play.

Guh!!

[Chromat]

you could also make a simple chi-squared test (it's a simple statistical analysis) for each your die. It requires that each die be rolled 100-500 times (the more the better) though, so large amounts of die testing takes time.

I tested some of my dice in this fashion and found some horribly skewed ones. I am yet to test my metal d20 i recently bought.

Anyway the there are tutorials on the net on testing your dies and on chi-squared test.

Hmmm... Maybe i could put together some tutorial...

[daggaz]

you could also make a simple chi-squared test (it's a simple statistical analysis) for each your die. It requires that each die be rolled 100-500 times (the more the better) though, so large amounts of die testing takes time.

I tested some of my dice in this fashion and found some horribly skewed ones. I am yet to test my metal d20 i recently bought.

Anyway the there are tutorials on the net on testing your dies and on chi-squared test.

Hmmm... Maybe i could put together some tutorial...

You still have to retest them. While highly unlikely, it IS a certain probability to roll some crazy runs... statistical outliers are included in the chi-squared algorithm for that reason. If the dice repeats the outlier, especially more than once, then you have a solid reason to believe they are skewed.

[FMArthur]

Spindowns are strictly worse at randomization than normal d20s, which I should remind you is the very purpose of having dice in the game in the first place. There is no reason to try it in place of regular, more random dice unless you want to get skewed results.

[arguskos]

Spindowns are strictly worse at randomization than normal d20s, which I should remind you is the very purpose of having dice in the game in the first place. There is no reason to try it in place of regular, more random dice unless you want to get skewed results.

Do you have an analysis that shows this? I'd like to see some test results on this score, since I've yet to see any.

I kinda agree, but since I haven't been able to find anyone who's actually run the results, I don't have any real proof.

[Gralamin]

Do you have an analysis that shows this? I'd like to see some test results on this score, since I've yet to see any.

I kinda agree, but since I haven't been able to find anyone who's actually run the results, I don't have any real proof.

One claim against them I have seen is that with a bit of practice and good enough dexterity, you can pretty easily roll a d20 in such a way it always ends up on one side. In a spin-down, this is an advantage. In a normal die, not as much.

[Powerfamiliar]

most d20s tend to be somewhat egg shaped so one part of the dice is favored. Normaly not a huge deal since while it will favor some numbers they will be a mix of high and low numbers. With spindowns this will ead to favoring high or low.