View Full Version : Help me with DnD math and Psionics please!

ScIaDrd

2010-08-03, 02:28 PM

So, Iīve been making my own system which makes heavy use of psionic mechanics, and while making classes Iīve hit a major problem, which lies in the power points chart. Its incredibly arduous to copy and even worse,there does not seem to be any easily understandable logic or system to it. See , itīs 3 at first level, 5 at 2nd, 7 at 3rd .

And I think Iīve figured a method to how it increases. I think the formula goes (PP at last level +N), where N equals 4 at 2nd level and increases by 1 at each successive level. So you have (2+4)=6 PP at 2nd level. That equals the proper value in the chart so all is good. Then it is (6+5)=11 PP at 3rd up until 5th where you have 17 PP from last level and should add 7 by my formula. Problem is, that adds only up to 24, while the chart says 25 power points.

So, here is the core of the problem , my formula does not work. And I, sucking at math as much as I do, canīt think of any way to improve it. For more proof of my fail scientific rigor, you get (46+10, where 10=N)=56 at 8th level compared to 58 by the table.:smallsigh:

So can the math capable Playgrounders among you help me out? Or, hopefuly, has anyone worked out a fuctioning formula?

Thank you a lot, but please note this is sorta urgent.

Critical

2010-08-03, 02:33 PM

So, Iīve been making my own system which makes heavy use of psionic mechanics, and while making classes Iīve hit a major problem, which lies in the power points chart. Its incredibly arduous to copy and even worse,there does not seem to be any easily understandable logic or system to it. See , itīs 3 at first level, 5 at 2nd, 7 at 3rd .

And I think Iīve figured a method to how it increases. I think the formula goes (PP at last level +N), where N equals 4 at 2nd level and increases by 1 at each successive level. So you have (2+4)=6 PP at 2nd level. That equals the proper value in the chart so all is good. Then it is (6+5)=11 PP at 3rd up until 5th where you have 17 PP from last level and should add 7 by my formula. Problem is, that adds only up to 24, while the chart says 25 power points.

So, here is the core of the problem , my formula does not work. And I, sucking at math as much as I do, canīt think of any way to improve it. For more proof of my fail scientific rigor, you get (46+10, where 10=N)=56 at 8th level compared to 58 by the table.:smallsigh:

So can the math capable Playgrounders among you help me out? Or, hopefuly, has anyone worked out a fuctioning formula?

Thank you a lot, but please note this is sorta urgent.

Why are you inventing the wheel, may I ask?

ScIaDrd

2010-08-03, 02:42 PM

Why are you inventing the wheel, may I ask?

Because copying it is way too big a hassle*-And also.. For SCIENCE!!!

Thatīs good enough justfication donīt you think?:smallcool:

* But if you consider if would have it copied it several times over in the time I spent typing that up. And looking up various Useless formulae on Wikipedia... *sigh*

Diarmuid

2010-08-03, 03:31 PM

Based on the progression from 1-3 of 3/5/7, you're looking at a formula of:

2N+1 where N = level

2*1+1=3

2*2+1=5

2*3+1=7

From there it should be pretty easy to move forward.

See , itīs 3 at first level, 5 at 2nd, 7 at 3rd. And I think Iīve figured a method to how it increases. I think the formula goes (PP at last level +N), where N equals 4 at 2nd level and increases by 1 at each successive level. So you have (2+4)=6 PP at 2nd level. That equals the proper value in the chart so all is good.

I'm confused why you think 6 = 5, or was there a typo somewhere in your post?

Urpriest

2010-08-03, 03:46 PM

To Diarmuid: 5 is powers known, 6 is power points.

To the OP: For a Psion: Powers known goes up by 2 at each level except 11th, 13th, 14th, 17th, and 19th, when they go up by 1. Power points look vaguely quadratic, I'm plotting them in Excel now to see whether they can be fitted to something more accurate.

Urpriest

2010-08-03, 03:52 PM

Excel says 0.8422x^2 + 0.2221x + 2.2675 is a perfect fit for a Psion's power points, where x is the level.

ScIaDrd

2010-08-03, 05:30 PM

Excel says 0.8422x^2 + 0.2221x + 2.2675 is a perfect fit for a Psion's power points, where x is the level.

You are seriously awesome, has anyone ever told you that? Thanks a lot. And what function did you use? Mine Excel-fu is far too weak for stuff like this.

FuryOfMetal

2010-08-03, 05:49 PM

you type the table into excel then create a line graph showing the quadratic. From there you either right click and then....well my excel-fu is useless without looking at it. But it should be self-explanatory once you have the graph, i remember doing it in college maybe 5 months ago.

Urpriest

2010-08-03, 07:00 PM

You are seriously awesome, has anyone ever told you that? Thanks a lot. And what function did you use? Mine Excel-fu is far too weak for stuff like this.

Put it into a line graph, then right click the plot to add a trendline. Tell it the trendline should be a polynomial of degree 2 (in this case). Tell it to put the formula on the plot, and voila. R^2 value 1 means perfect, lower means a weaker fit.

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