dispel chance
 

I read some older posts regarding dispel.

I wasn't sure about something so I'm bringing it up again.

I will use an example as reference.
Say someone cast a GE that costs 70 gems and added 30 more for strength.
So...

what is the chance of failure if a dispel is cast with no extra gems?- is it 100%?

what is the chance of failure if a dispel is cast with less then 30 gems?- is it 100%?

what is the chance of failure if a dispel is cast with exactly 30 extra gems?

what is the chance of failure if a dispel is cast with more then 30 extra gems?- Is it a guaranteed success (0% failure) or a function of the added gems?

TIA all experts.

Re: displel chance
 

I think there's an open ended roll involved, so there are no guarantees, no matter what you pay http://forum.shrapnelgames.com/images/smilies/wink.gif

Re: displel chance
 

If the dispeller's extra gems spent + skill in Astral magic (or perhaps skill above that required to cast dispel) + oeD6 is greater than the globals extra gems spent + oeD6, the global will be dispelled. So:

Very high chance of failure.

Less chance, but the odds are not good. (depending on how many less than 30 were spent)

Basically 50-50, with a slight edge for a powerful Astral caster.

Arbitrarily low, depending on how many extra gems were spent.

Re: displel chance
 

quote]Truper said:
If the dispeller's extra gems spent + skill in Astral magic (or perhaps skill above that required to cast dispel) + oeD6 is greater than the globals extra gems spent + oeD6, the global will be dispelled. So:

Very high chance of failure.

Less chance, but the odds are not good. (depending on how many less than 30 were spent)

Basically 50-50, with a slight edge for a powerful Astral caster.

Arbitrarily low, depending on how many extra gems were spent.

[/quote]

This raises an interesting probability question.
What is best cost effective strategy for dispell.
Two extremes, on the one hand trying to dispel with no extra gems. If attempt fails try again.
On the other hand cast dispel with a Hugh amount of extra gems say (relating to the example) 60 gems.
so gem wise three dispel attempts cost the same as one with 60 extra gems.

Another factor to take into account is that actually the amount of extra gems spent to cast to GE is usually unknown.
It could be anything from 0 to whatever.

I want to plot a graph of the chance of dispel dependent on the factor of extra gems.
A basis for this graph is probability of one oed6 to be greater then another independent one.
Say Xa = result of oed6, Xb = result of oed6, P(Xa>Xb)?
For regular d6 I think it something like 15/36.
For oed6 I am not sure. I think is something along the line of:
15/36 (sum of events of Xb less then Xa in first roll) +
1/36*(15/36 + 1/36*(15/36 + 1/36* ...
(event of first roll ties on 6 and then second roll)

I could be entirely wrong so if you are a math expert and reading this I'd appreciate any comments to my reasoning.

Re: displel chance
 

To get an idea of the probability of successful dispel as a factor how many extra gems the dispelling mage is using I simulated things for d6.

The attached graph is for d6.
I think that the graph for oed6 would be similar except that it is asymptotic to 1.
Therefore I think that if the caster will add 3-4 gems extra to what the GE caster used he would have a good chance for dispelling (~80%-90%).
more then that would give diminishing addition to the chance of dispel.

Well probably that's an obvious conclusion, but I find it useful nonetheless http://forum.shrapnelgames.com/images/smilies/happy.gif

Re: displel chance
 

I have never seen a dispel cast with more TOTAL gams than the original spell fail. I have never seen a dispel cst with less TOTAL gems than the original spell succeed.

This leads me to believe that there is no open ended die roll involved, and that the bigger spell simply wins. Every time.

Note, the spell doesn't seem to care about how many extra gems are spent, only how many total gems are spent. So a Burden of Time with zero extra gems would need 41+ extra gems to dispel (because a base Burden of Time has 70 gems in it, and the base Dispel has only 30 astral Pearls in it).

Note2, it looks like it's the total gems you actually spent, so if you have been casting spells out of a magic bonus site, it's that much cheaper to dispel them as well.

Note3, this is probably why the minimum Dispel is 30 pearls, as that is coincidentally the minimum cost of any Global Enchantment (Stellar Brilliance, as it happens).

-Frank

Re: displel chance
 

Are you sure?! That would mach the dispel MUCH weaker, than i though.

Re: displel chance
 

Accoring to Kristtofer O:

"There is an openended six side die added to the gem input of every global and dispelling attempt."

I tried to find a definative statement of the way dispelling works, but the above quote was the best I could come up with.

Re: displel chance
 

I have yet to cast either, so I just may need to try so I can see what your talking about. But how do you know how many gems were used by the enemy in an enchantment?

Re: displel chance
 

I hope this is not the case. Because I agree, that would make Dispel much weaker than I thought, if it counts TOTAL gems and not extra gems.

<< crosses-fingers >>

Re: displel chance
 

That's the "joy" of casting Dispel, it would seem (my first time casting it in a game, results later today). You start asking yourself, how much did he put into that global initially, just the base gem cost, or some extra gems. And if so, how many extra gems should I "waste" to ensure it gets dispelled.

At least that's how I see it.

Re: displel chance
 

Wow, If that is accurate it really makes dispel quite weak.
I wonder how come it's not in the manual or something.
A confirmation from the Devs would help a lot.
@Truper, can you tell us where did you get this information regarding dispel chance?- Does it agree with your experience?

Re: displel chance
 

There is an explanation oed6 math in Sunray's site.
For some reason though I can read the whole document but when it get's to the part of giving the formula (p(n)= ...) it is left blank. Maybe it's a problem with open office...

Also I found some interesting discussion in the old ibm strategy forums.
It looks like it's about dominions PPP. It also seems to back Truper's explanation.

I admit I'm completely http://forum.shrapnelgames.com/image...s/confused.gifpuzzledhttp://forum.shrapnelgames.com/image...s/confused.gif here.

Re: displel chance
 

this is wrong, I just tested it in sp. First I cast a well of misery(80 total gems) , then I dispelled it with a 20gem powered dispel.

Re: displel chance
 

Yes! I was somewhat disappointed with dispel in light of FrankTrollman's explanation.
Thank You Turin for testing this.

Re: displel chance
 

I remember testing it. The global enhancement strength is equal to a number of extra gems put in the spell + number of extra level (above required) of the caster. I haven't identified any random element, but that's a random element - one is not guaranteed to detect it by a serie of experiments http://forum.shrapnelgames.com/images/smilies/happy.gif I'm sure that if there's a random element, it is not large, so dispel with 969 extra gems by a decent astral mage dispels pretty much anything worth dispelling http://forum.shrapnelgames.com/images/smilies/happy.gif

Re: displel chance
 

how about an idea for a detection spell that tells the caster the strength of a global enchantment.

It can be used with dispel to optimize the dispelling chance vs astral gems spent ratio.
It can be a level 9 spell with high astral requirements (say astral 6) and low gem requirement (say 10 astral).