Sunday, January 23, 2011

Universal Probability Comparison Chart

Hill Cantons is working on finding a hidden retro-clone in the old Judges Guild Universal system.  To that end, he has posted a couple of references to information about their old system.  Interesting stuff.

In one document lurked a little gem (at least I think so) that's handy if you never use it.  :)

This chart cross-references the rolls of 1d6, 2d6, 3d6, 1d20 and d% with each other.  Seems like in certain situations this could be extremely useful.  I know that with this chart, and d%, I could probably run an entire session of my OSR game.

I might have to try that sometime...


PS: Go Bears!!!

10 comments:

JDJarvis said...

the probability chart is certainly inaccurate if the scores are supposed to be equivalent probability.

A 1-5 on a d100 roll is the same as a 1 on a d20, using math the chart however has a 1-7 on d100 being the same as 1 on a d20.

Spawn of Endra said...

Yeah, and their 20 corresponds to 3% on the d100. Does that reflect a mechanic specific to the JG universal system?

Spawn of Endra said...

And the d6 makes no sense either, it should break into ~16-17% increments. What is this table supposed to be used for? This seems pretty idiosyncratic for a universal system. Odd.

Jim said...

@JDJarvis
@ Spawn -- you're right. The probabilities are off. I guess that's one more example of how eccentric JG is/was...

Spawn of Endra said...

Sorry about your Bears, btw. Is the chart presented as a probability conversion or something else?

Anonymous said...

Eccentric, there's a good word.

Jim said...

@Spawn -- originally, I thought it might do as a probability conversion; but, as JD pointed out, it's not correct. I've just posted a corrected table that is still a bit off at the ends for 3d6, but should work in a pinch.

Spawn of Endra said...

Right, Jim, I know what WE thought it was supposed to be when we first saw it, but *What did the Judges Guild intend it to be?* What document did this come from? Is there explanatory text of how to use the table?

In a way it's consistent with its wrongness, e.g., the low numbers are given higher probabilities, like the 2 on the 2d6 and the 3 on 3d6, which should be very rare. And they are also flat distributions instead of bell curves. So the fact that they weight these wrongly in the same way makes me suspect that there is some other logic at work here.
And why only a universal table for d6, 2d6, 3d6, and d20?
(Sorry to beat a dead horse here, but I'm somewhat intrigued now.)

Anonymous said...

If it's not a mistake, but a choice, it would be interesting to know what they intended it to be. Especially if people are trying to make some sort of retro-clone out of the system.

Jim said...

Sorry all, don't mean to be dense -- the document is here: http://www.judgesguild.org/downloads/Universal%202.0.pdf and the chart is on the last page. There's a discussion of the range of attributes "going from 1 to 20" with adventurers ranging from "3 to 18", but there's no acknowledgment of the skewed table that I can find.