Complex dice roll probability calculator. (sh.itjust.works)

submitted 6 days ago* (last edited 6 days ago) by illectrility@sh.itjust.works to c/rpg@ttrpg.network

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I made a web page where you can simulate a complex dice roll sequence with conditionals (e.g. re-roll when roll is a 1) using a Python-like syntax. (Click the "Toggle Syntax" button to view examples)

It needs a second to load because it has to load a Python interpreter in the background (I'm not good at web development) but once that's done, it works really well.

It's still very barebones and I still have to work out some problems.

Maybe some of you could use it, though.

There's also just the Python version available to run locally here

Everything is GPLv3, enjoy!

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[-] Wutchilli@feddit.org 10 points 6 days ago

Nice Work, but did you forgot to link the Website?

[-] illectrility@sh.itjust.works 14 points 6 days ago* (last edited 6 days ago)

Yes, yes I did... It's here

Thank you for pointing that out

[-] pennomi@lemmy.world 7 points 6 days ago

Extremely impressive! I wrote a dice probability calculator myself recently, but abandoned perfect calculations in favor of a million roll simulation. What you have done is really quite lovely.

[-] illectrility@sh.itjust.works 9 points 6 days ago

Thank you very much. I, too, initially used a sampling approach but that was obviously inefficient and inaccurate. Getting this to work was a HUGE pain so it's nice to read some kind words about it, thank you

[-] AnExerciseInFalling@programming.dev 5 points 6 days ago

This is super cool!

Does it support things like max/min to simulate advantage/disadvantage?

It would be really cool to mathematically compare different kinds of rolls, like the cascading dice damage post from a couple weeks ago (even if its not built into the notation, just writing out the logic by hand)

[-] illectrility@sh.itjust.works 4 points 6 days ago

No, there is no advantage or disadvantage functionality. I made it purely for balancing, so finding out the average damage a character would do. In that case I would just write out all the different rolls the character would do when attacking and have the program calculate using that. It's pretty barebones

[-] AnExerciseInFalling@programming.dev 3 points 6 days ago

Still a very cool project! Fun to play around with

[-] neodc@sh.itjust.works 4 points 6 days ago

How does it compare with https://anydice.com/ ?

[-] illectrility@sh.itjust.works 3 points 6 days ago* (last edited 6 days ago)

Pretty similar but I couldn't get re-rolls to work on there. That's the main reason I made this

[-] jcr@jlai.lu 1 points 6 days ago

I am working on a dice expression evaluator on my side, and I will certainly reuse your code if I can ! Thanks for giving the example, as a GNU enthusiast, it is very nice ! Great job making it work !

[-] illectrility@sh.itjust.works 1 points 6 days ago

Best of luck to you. I think my code is quite messy but if you can use any of it, feel free!

[-] Kitathalla@lemy.lol 1 points 6 days ago

Cool. I used to have an app that would do this and it was great to play with for various scenarios. Nice to see a website version.

[-] illectrility@sh.itjust.works 1 points 6 days ago

What was the app called and is it still available?

[-] Kitathalla@lemy.lol 1 points 6 days ago

No, it was oooold. Like, ipod touch old. It didn't make it past ios 5, I think. It's why I'm loving your webpage.

[-] illectrility@sh.itjust.works 1 points 6 days ago

Okay, would've been interesting to see

this post was submitted on 25 Feb 2025

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