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Rollable Tables & Probabilities

Once upon a time i created a Rollable Table with 325+ entries.  Each entry had a potential weight between 1's and 1,000's. The total combined weight of all entries was 80,000.  Something i found happening was that whenever i referenced the Table via a macro, that it appeared to only reference other entries in close proximity to that initial random check point. Since then, i have modified the Rollable tables.  There are now eight of them, each only weighted a total of 100.  The random number generation seems to work a lot better now, but maybe i'm only seeing what i want to see.  What i do know is that dealing with a bunch of separate smaller Rollable Tables makes my macro trigger situation a lot more complicated -something which i don't like! The reason why i had the entries in the old Table weighed at such a wide range was that for example, lets say i had an Iron Flask appearing with a weight of 200 out of 80,000 on the list.  Lets say that 1 out of 100 of those Iron Flasks held an imprisoned Xorn, for a specific weight of 2.  Weighing with large numbers theoretically allowed me to enumerate small sub-divisions within a generated item, but in reality so that i could add every potential type of Iron Flask to my list. But in actual practice, the random number generation did not seem to like this setup. So what am i requiring too much of the Rollable Table?  What am i doing wrong here?  :)
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Pat S.
Forum Champion
Sheet Author
It has been noted that the larger your rollable table the less random it becomes. It breaks down after a few hundred entries. Have you thought about having an API script built to handle multiple tables and all the required rolling for them? Not sure if it has been done or is even doable but it is a thought you could ask in the API forum about.
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Pat, i have really tried my best to be self sufficient with these things, & would hate to ask for some one else to do it for me.  But it is not beyond my pride to ask for help if there is a way i could participate in the process of creating the end-product.   The reason why the table was so large is that it contained the 5 Miscellaneous Magic lists from the AD&D1e DMG, plus the Artifacts/Relics list, and the 2 additional Miscellaneous Magic lists from Unearthed Arcana.  So a total of 8 lists of d100 each. Do you have a reference that explains exactly how the tables become less random as they grow larger?  I would like to study this more.
TheAaron did make a script that can handle nested rollable tables. Might help with the randomness issues.
Hmmm...  sounds Sexy!  :)   I will have to take a look.
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Pat S.
Forum Champion
Sheet Author
Goblintrain said: Do you have a reference that explains exactly how the tables become less random as they grow larger?  I would like to study this more. I only know about it in reference from a few mods talking about it elsewhere.
Can we get some official word on this issue, namely the apparent non-randomness of the rollable tables? I ask because I am about to make a number of large tables for generating randomized information. I intend to use The Aaron's script mentioned above, but some of the tables are still going to have 100+ items in them. If this is going to lead to nothing but frustration as I roll 20 items all from the "R" section of my rollable table, and never get any "M"s, then I'm not going to do it this way; I'll just keep using the paper charts instead. -Phnord, the guy who really, really likes (true) randomness.
Well, you are a Pro subscriber... you could do it all via the api. Would definitely maintain its randomness then.
I'm a Windows '98 man!  Why the hell would i use API!?  :)
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PaulOoshun
Marketplace Creator
Phnord Prephect said: Can we get some official word on this issue, namely the apparent non-randomness of the rollable tables? Seconded, I would like to make use of them for various things and the degree of randomness and the breakdown points are important.  Is it only over x hundred?  What is x? 
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Pat S.
Forum Champion
Sheet Author
Alan H. said: Phnord Prephect said: Can we get some official word on this issue, namely the apparent non-randomness of the rollable tables? Seconded, I would like to make use of them for various things and the degree of randomness and the breakdown points are important.  Is it only over x hundred?  What is x?  I went looking around (digging in archives actually) and couldn't find what I thought I saw other than a report or few in the forums about the rollable tables not rolling as random as they should so take it as it is. I did find  Aaron's Recursive tables script which would might solve the problem before it starts.
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Subscribing for api access shouldn't be the long term solution for fixing a bug with the randomness of tables, if such a problem truly exists.
Honeybadger, that is very true, and i believe the problem does exist.
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PaulOoshun
Marketplace Creator
Could one of the Moderator team please ask Riley or Steven to drop by with info on this?
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Riley D.
Roll20 Team
Okay, seriously, this thread is pretty crazy. It's basically gone from someone suggesting that they might have noticed off-hand that rollable tables aren't random, to someone else confirming they are pretty sure that's the case (even though they don't remember where they heard it from), to people getting upset because they shouldn't have to use the API to make rollable tables random.  Rollable tables are random and working properly as far as I know. Like any other piece of randomness on the site, just because you didn't get what appeared to the "naked eye" to be a totally even distribution of results when you made a few hundred rolls on an 80,000 item table does not mean they are not random. If someone has an actual bug to report about rollable tables being random, feel free to file it in Bug Reports and I will take a look. Obviously something like rollable tables not working *as intended* is not something that we are relying on the API to fix, and I have no idea where that idea even came from.