3D dice results are not random

[Trenloe]

I emphasize this again: Just by switching from Classic to Unity my chances to roll a 1 or 20 dropped by 10%.

That’s misleading - 10% of what? 10% suggests that it’s going to happen 1 in 10 times. For a 1 the drop was approx 5,000 rolls out of 1,000,000 rolls - 0.5% of the total rolls, 1 in 200 times. So, statistically, if you roll a d20 200 times in a session one of those rolls that wasn’t a 1 should be a 1, and one of these rolls that wasn’t a 20 should be a 20, but we don’t know what roll result we’d need to change.

But, as FGC is above the mean for a 1 on a d20, the actual FGU deviation from the mean (each result should occur 50,000 times in 1,000,000 rolls) and taking your results from post #96: 50,000 - 46,177 = 3,823 rolls less than the mean. This results in a roll of 1 on a d20 not happening when it should, statistically, 1 time in 261 rolls. For most of my games (and I play a d20 based system most often) that wouldn’t even be once per session.

Like I said, this is an interesting theoretical presentation of data but needs some perspective on the actual impact to our games.

[Jiminimonka]

I'm going to upload my chat log tonight. And next session on Monday. And especially when players think the rolls are bad....

[Weissrolf]

That’s misleading - 10% of what?

10% lower chance to roll a 1 or 20 in Unity relative to Classic, consistently. While Classic tends for a more "extreme" game, Unity tends for a less "extreme" game.

So, statistically, if you roll a d20 200 times in a session one of those rolls that wasn’t a 1 should be a 1, and one of these rolls that wasn’t a 20 should be a 20, but we don’t know what roll result we’d need to change.

Averaged over time you are correct. But every single D20 roll in FGU has a 7.5% lower chance to hit a 20 than it statistically should have, consistently. And every double roll has a 17% lower chance to hit double 20s, consistently. My dice are all weighted and I cannot grab into my satchel to get another one other than using the Instant Dice extension.

But, as FGC is above the mean for a 1 on a d20
...For most of my games (and I play a d20 based system most often) that wouldn’t even be once per session.

Again, this may be correct over averaged period of time, but every single die roll has a 2.5% higher chance to hit 20 than it should have. That being said, for the D20 the deviation is 3 times smaller in Classic than it is in Unity, the latter of which I consider more seriously bugged for the time being (not having checked Classic at detail).

Like I said, this is an interesting theoretical presentation of data but needs some perspective on the actual impact to our games.

The perspective is that every single roll is affected even when it does not hit you over the head while you play games. It may even be that someone playing on OS X has consistently differently weighted dice than you, so either of you is always getting lower chances for a D20 than the other player. It may not bother many of the veterans around here, but at least people should be informed and get a chance to switch it off.

I am a GM and every time my players roll sh*te someone in the group starts explaining how computers cannot roll proper random numbers. Frankly, I would like to get that discussion out of my games, especially in the middle of the action. There are easy to implement statistically good PRNG algorithms out there and we are using something that's over 20 years old and then put an even less random system on top of it just for the eye candy.

[Weissrolf]

I'm going to upload my chat log tonight. And next session on Monday. And especially when players think the rolls are bad....

FGU's rolling would have to be even much more blatantly weighted for a human to see any pattern in a log full of different dice being rolled. I am already surprised about the level of weighting present, but it likely is not so bad that you could see it by looking hard at log files. The only kind of human pattern recognition you can hope for is from the bit based noise images I provided.

[Trenloe]

So, I keep saying that we need to have perspective and look at how this relates to our actual gaming experience.

A while back, Doug did some campaign d20 roll analysis based off GMs submitting their chat log, info in this thread: https://www.fantasygrounds.com/forum...ame-Statistics

Let's look at the first chatlog analysed - from post #2 in that thread. The chatlog shows 9 gaming sessions - a couple of those are shorter than others, so let's go with 8 gaming sessions. The results are shown here: https://www.fantasygrounds.com/calen...ts.php?id=2503

Specifically, let's look at the d20 results: https://www.fantasygrounds.com/calen...gory=d20+Rolls Here is that data presented in Excel:



Keep in mind this is for FG Classic. For a direct comparisson we need to look at the FGC data here: https://www.fantasygrounds.com/forum...l=1#post561913 From the two specific pieces of data supplied: #2: 5.21% vs. #10: 4.80% for 1,000,000 rolls, we see that across 8 gaming sessions, with 976 rolls, a 2 occurred 5.02% of the time and a 10 occurred 5.12%. Looking at rough data from the graph, we'd expect this dastardly #1 roll to occur 5.1% of the time - but it's actually 4.4% of the time - well low in this game for FGC (and also well below the statistical analysis of the #1 result in 1,000,000 simulated rolls for FGU).

I'm sure if you looked at other real-game statistics (available in that thread) you'd see differing results. See here for example with a lot more rolls: https://www.fantasygrounds.com/calen...gory=d20+Rolls or here for a single session example with not so many rolls: https://www.fantasygrounds.com/calen...gory=d20+Rolls

So, what can we take from this? In a real-game situation the statistics of simulated 1,000,000 d20 rolls don't apply. Sorry, Weissrolf, but that's simply the cold facts. And most people who deal in statistics would have foreseen this - because simulating something that happens a few hundred times across a few hours by rolling 1,000,000 times gives statistics, but doesn't represent real (virtual) world experience.

Can we please put to bed the notion that FGU is broken and cheating and playing a rigged game with weighted dice? The statistics are interesting, but as the above actual game chat log analyses show, statistics like this don't directly cross over to real-game experiences. And the devs certainly should *not* drop everything to try to address something that has little-to-no impact on our actual gaming experience.

[Jiminimonka]

I am a GM and every time my players roll sh*te someone in the group starts explaining how computers cannot roll proper random numbers. Frankly, I would like to get that discussion out of my games, especially in the middle of the action. There are easy to implement statistically good PRNG algorithms out there and we are using something that's over 20 years old and then put an even less random system on top of it just for the eye candy.

And thus we come to the point. Humans blaming their dice rolls on some external source - bad dice, bad luck, bad software. As always humans looking for something to blame.

I have had sessions where the orcs shooting arrows at 1 target missed 15 times in a row... and the player didnt complain at all. Those orcs sure did though.

Save your chat logs and upload them here next time the players complain.

[Trenloe]

Averaged over time you are correct.

Again, this may be correct over averaged period of time...

These statements contradict the data you're presenting. Rolling 1,000,000 d20s and presenting the data for those 1,000,000 rolls together is "averaged over time". All of the statements you make like "7.5% lower chance to hit a 20" and "every single die roll has a 2.5% higher chance to hit 20 than it should have" is based off the "averaged over time" data you've collected.

Anyway, please see my "real game" post above. I'm moving on now, this thread is nothing more than a bunch of interesting statistics. Post #125 above shows that these type of statistics don't directly correlate to an in-game experience.

[Weissrolf]

So, I keep saying that we need to have perspective and look at how this relates to our actual gaming experience.

I do not disagree.

A while back, Doug did some campaign d20 roll analysis based off GMs submitting their chat log...

While again I agree that taking data out of real games can be helpful, we have to take three things into consideration here:

1) The data provided does not seem reliable. One of your linked logs lists results of 0 (zero) on a D20 and the other one lists a 22 on a D20. So let's agree that if we make use of another database then we need to make sure that we don't get completely wrong results. ("Five is right out."). I already noticed this a few weeks back when I first read and posted in Doug's thread.

I fully expect you to scrutinize the data presented by me when you add to the discussion. Everyone can only win by working together and revealing flaws in others data, so that it can be corrected.

2) While the data represents real gaming sessions the data basis is rather (too) small to even do statistical analysis on it. I did not do 1 mio. rolls because I ever thought this would represent how many times we roll per game or even per campaign, I did so to get statistically meaningful results and a more consistent look into the black box.

Chance is "the level of possibility that something will happen", it still might not happen at all for a long time. This brings us to:

3) Analysis of my data suggests a periodicity that we have yet to make tangible and find out how it affects our real games. While all those 1 mio. rolls statistics are not meant to represent periods of real game-time those 200 D8 rolls are more in the ballpark of "real". Unfortunately other dice than D8 cannot be converted into bit-streams so easily (if at all?), so we lack a better understanding of possible D6, D20 or D100 periodicity.

And locking at chat-logs likely will not reveal such, because looks less like periods of consistently low vs. high rolls, but more periods of consistently rolling certain numbers over other numbers. You could argue that it's not relevant then, but personally I wouldn't like my players being stuck in a period of numbers that deterministically make or break their rolls.

And here comes a solution like the "Instant Dice" extension to the rescue, because with all its flaws (C rand) it still behaves so much more random that we fight less dragons when we have to deal with it. It's a crude workaround, though, and I would like for FG's physics engine to do much better than it currently does, both statistically and visually (get rid of the "floating" dice, we are not playing on the moon, despite using "Lua").

[Weissrolf]

And thus we come to the point. Humans blaming their dice rolls on some external source - bad dice, bad luck, bad software. As always humans looking for something to blame.

Except that with 3D click/automation rolls those humans are correct, they are weighted.

[Trenloe]

2) While the data represents real gaming sessions the data basis is rather (too) small to even do statistical analysis on it.

I agree. But what I'm trying to get across is that statistical analysis is interesting - but it does not translate to real-game experiences. We don't roll thousands of dice a session, so averages over time data that has deviations of only a few percent doesn't apply to any noticeable impact on our games. If you look at multiple sets of data from real world sessions (I've given the link to a few above) you see the statistics are all over the place.

This proves that the "oh woe is me, FG is broken and needs fixing NOW!" train of this thread, based of purely statistics, does not translate into any impact on a real gaming session. To me, and I'd imagine most people who use FG to play RPGs with their friends, that is all that matters.

Keep going with the statistics, if that's what floats your boat, but please stop the claims the FG is broken and needs to be fixed. Because, for all gaming intents and purposes, it isn't.