Kind of off-topic dice/probability question.

[kablammo]

I couldn't find a suitable forum, but if there is one, feel free to move this post.

My friends and I just finished a session in which the DM used a D10 instead of a D8 to roll for damage. He simply re-rolled if the D10 landed on either a 9 or a 10.

My math noob question is: does this method yield exactly the same probabilities for landing on a 1 through 8 as rolling a D8?

Short answer is probably yes, but for some reason I feel like there's more to it.

 

[kitcik]

Absolutely yes, exactly the same, no question.



(assuming they are both fair dice of course)

 

[kablammo]

Thank you sir!

 

[RUMBLETiGER]

Seconding [MENTION=98256]kitcik[/MENTION]. You've got an equal chance of a 1 through 8 coming up, with the annoyance of having to spend more time re-rolling occasionally.

 

[Jimlock]

let me see....


5475/76*xY*767?*/64/6536,65/X/Y*/ = 7564754,6*76x/2 = x/97688*4

hmmm...

...yep... its the same...

 

[anest1s]

Think it like this:

Infinite mathematicians walk into a bar.
The first one asks the barman one glass of beer.
The second one asks for 1/2 glass of beer
The third one asks for 1/4 glass of beer.

Ok I got it says the barman, and serves 2 beers.


(Well instead instead of mathematicians you have rolls, instead of beers you have dice and instead of half you have 2/10 but its the same logic)

 

[Water Bob]

Tell your DM to stop pussyfootin' around and use the right damn die! It doesn't matter if the d10 yields the same probability. My gods, son! This is D&D! Use the right tool for the job. Don't use a pair of pliers when you need a wrench.

The d8. It's an unloved die.

But it's there for a reason. Let it serve its purpose!

 

[Patryn of Elvenshae]

Tell your DM to stop pussyfootin' around and use the right damn die! It doesn't matter if the d10 yields the same probability. My gods, son! This is D&D! Use the right tool for the job. Don't use a pair of pliers when you need a wrench.

The d8. It's an unloved die.

But it's there for a reason. Let it serve its purpose!

The d12 hears you call the d8 an "unloved die," and spits on you, then runs away crying.

 

[Rhun]

The d12 hears you call the d8 an "unloved die," and spits on you, then runs away crying.

QFT! My d8 gets rolled like ten times to every time my d12 gets rolled.

 

[Water Bob]

The d12 hears you call the d8 an "unloved die," and spits on you, then runs away crying.

The d30 looks over at the d12 spitting on the d8 and just sits there. The d30 doesn't even try.

"Hell," d30 says, "At least d12 is one of the Big Six."

Then d30 looks up when d100 passes by, still bitching about those friggin' twin d10 brothers who took his place.