Probability Calculation

[Bidmaron]

Sorry, damned but you are wrong. It is .0000282%. Fundamental probabaility. If the odds of an event are x then the odds of not having the event are 1-x. The odds of an event happening EVERY TIME (in this case the event not happening every time) is always x raised to the power of the number of iterations. Thus the answer is (1-x)^n. In this case, x is .14 and n is 100.

[damned]

lets keep it simple.
we have 100 possible numbers that could be rolled.
we have in this case 3 numbers that didnt get rolled.
there is a 97% chance that you wont roll those three numbers.

now before you argue you will see that my math is exactly the same as yours.

[Bidmaron]

Damned there is no context for that. What three numbers are you talking about? The OP said only 14%. There is nothing about 3 rolls. What am I missing? He asks what is the probability after 100 events of not once getting an event that has a 14% probability of occurring. You must be a mind reader or know some back context because my answer is math fact for what was originally asked.

[shadzar]

he is going off post 6 where the goalposts were moved.

[Bidmaron]

Oh, well, dropping it since it doesn't seem the poster can put together a cogent scenario he wants to examine. Sleep deprivation does funny things....

[Trenloe]

Sleep deprivation does funny things....

No, that's just John!

[JohnD]

No, that's just John!

Indeed.

[2bfjs]

On the subject of probability, what is the effect of Advantage and Disadvantage in D&D 5e? My calculations indicate when an 18 or greater is required to hit 15% probability of success, with Disadvantage 2.25% probability, and with Advantage 27.25%. What are your opinions on how best to handle converting adventures from previous editions to 5e with regard to game balance and Advantage/Disadvantage or is it not a factor to consider?

[Trenloe]

What are your opinions on how best to handle converting adventures from previous editions to 5e with regard to game balance and Advantage/Disadvantage or is it not a factor to consider?

It's part of the 5E rules used for playing 5E, I wouldn't consider it too much of a factor when converting from older systems. The main thing to consider is that 5E (mostly) uses the advantage/disadvantage mechanic instead of specific numerical modifiers ) there are some exceptions, but in general adv/dis is used instead of a specific modifier to d20 rolls. If you feel some previous version ability would be better served rolling with advantage or disadvantage, then go with that. Otherwise, I'd recommend not spending to much time converting old ruleset "stuff" - find an equivalent 5E NPC, ability, etc. and use that - with appropriate modification to fit the aim and flavour of the original.

[shadzar]

also, none of the old SoD will work with 5e due to death saves.
there is tons more that 5e doesn't account for that can be seen in Tales From the Yawning Portal, where the adventures just don't work with 5e since 5e is designed around being super heroes of the world to begin with, rather than being common-folk that just happen to be adventuring.

You basically have to consider that 5e is D&D in name only. Tomb of Horrors can still be deadly due to insta-death things like Petrification that bypasses Death Saves. So the odds of converting would be like said during 3.0, you just recreate things with the closest approximation to what you had with 2nd and just go with it.

Better to rewrite the whole adventure for 5e than to just try to convert a few things due to the assumptions of older editions and newer editions.

think about things that didn't exist:
perception checks
all the other skills
any feats

then find out what the older edition adventure was trying to do and emulate that with NPCs, monsters, traps, environs, etc as best you can with 5e.

there is 100% chance, that just plugging in the same named things between 5e and an older edition will yield less than wanted results.