Percentile Dice Question

[Nefreet]

Try 'em out. We didn't do thousands of rolls, but we all sat down one night before game with three of my roommate's dice and kept rolling. Two of them, the older ones, consistently came up with higher numbers. The 19 was next to the 18 was next to the 17, etc, and the numbers spiralled downward towards the 1 side from the 20 side. Regular gaming dice have the numbers all over.

[Darkwolf117]

Yeah, MTG's dice are spindowns (or at least, that's what I've called them and/or heard them called), because they're meant for tracking life more than actually rolling. That way 20 (or the set symbol) is next to 19, next to 18, and so on, so that it makes it easier to locate the number you want whenever you take damage or gain life.

At least, that's always been my assumption anyway.

Edit: At any rate, yeah, I've never seen a GM or players who abide using spindowns in place of d20s. Whether or not they have more chance for one number than another, I don't know, but it's certainly much easier to shoot for a high number versus a low number when all the highs and lows are grouped together, rather than a standard d20's distribution.

[agentJay]

Darkwolf117 wrote:

Yeah, MTG's dice are spindowns (or at least, that's what I've called them and/or heard them called), because they're meant for tracking life more than actually rolling. That way 20 (or the set symbol) is next to 19, next to 18, and so on, so that it makes it easier to locate the number you want whenever you take damage or gain life.

At least, that's always been my assumption anyway.

Edit: At any rate, yeah, I've never seen a GM or players who abide using spindowns in place of d20s. Whether or not they have more chance for one number than another, I don't know, but it's certainly much easier to shoot for a high number versus a low number when all the highs and lows are grouped together, rather than a standard d20's distribution.

We called them "roll down" dice. due to the way the numbers roll down from 20 all the way around the die.

They come in "Star Wars" sets as well, we have a few people that were using them till someone noticed they were "roll down". The offending player claimed innocence saying, "I never knew to look at the dice to see how the numbers were placed."

[Zandikar]

last night a a PFS game the Dm roll hit chance vs my Seoni while invisible. roll the double digit d10 rolled a 00, the Dm claimed it was 100, while i said 1 in 10 chance for it to be 100, and continued to say it was possible to get 109% and never 1-9. is there rules in any of the books how to rule this/roll percentiles? saying how i'm/we're correct?

i saw his resoning untill he mentioned off hand about the more then 100% to another player.

for the time being he decided to have the mini-boss channel negative instead for both more dmg, and and we're playing higher tier lvl 7 rather then low tier.

this is important still important as i'm running an armor sorcerer with a cleric dip. any extra help would be helpful.

[DharTook]

If you are using two d10 to simulate a d100, 00 should be read as 100, but 02 should be read as 2. This gives the results you'd like from a d100: an equal probability of every number from 1 to 100.

If you'd like, think about one die as the tens place and the other die as the ones place. They don't specify any other information. When you roll 100, your tens place is 0 and your ones place is 0. Lots of numbers have a tens place of 0 and ones place of zero, but the only number that meets that criteria that I want a d100 to roll is 100.

[DharTook]

I just realized that I failed to comprehend the ACTUAL heart of the issue: Should 00 be a success or a failure for the 50% invisible hit chance?

First off, if you actually want a 50% hit chance, it's probably easiest to ignore the d100 and just use one die. For 50%, you can use any even sided die. Make evens a success and odds a failure. The probability will be exactly 50%.

If you DO use a d100, then you should count 00 as 100 IF you make sure to include 50 itself as belonging to the "50 and below" group.

Or, to simplify: Under the standard convention, for a 50% miss chance, 01 - 50, including 50 itself, should be a miss. 00 and 51-99 should be a hit.

[YogoZuno]

Percentage dice are intended to be 1-100, not 0-99. If you treat the 00 as 0 rather than 100, then the target for a particular percentage has to be dropped by 1. So, if 00 is 0, and you have a 20% chance, you would be looking for 0-19, not 0-20.

There are other conventions to think about too - if there is a 50% miss chance, is 1-50 a miss, or is 51-100 a miss? So long as you declare ahead of time, it doesn't matter, but if you don't declare or follow a convention, arguments can happen. For myself, I follow the convention that low is bad and high is good, so 1-50 is a miss.

[DharTook]

YogoZuno wrote:

Percentage dice are intended to be 1-100, not 0-99. If you treat the 00 as 0 rather than 100, then the target for a particular percentage has to be dropped by 1. So, if 00 is 0, and you have a 20% chance, you would be looking for 0-19, not 0-20.

There are other conventions to think about too - if there is a 50% miss chance, is 1-50 a miss, or is 51-100 a miss? So long as you declare ahead of time, it doesn't matter, but if you don't declare or follow a convention, arguments can happen. For myself, I follow the convention that low is bad and high is good, so 1-50 is a miss.

I too prefer 1-50 is a miss, but using the convention that "whatever is described happens when the roll is low." That is, I use 1-50 because it is described as a 50% MISS chance rather than HIT chance. I use 1-20 for 20% miss chances for the same reason.

Of course, there's nothing wrong with using a different convention. My concern with a good/bad division is that it depends on perspective. ("Good" from the player's perspective? "Good" from the attacker's perspective?)

[seebs]

I have always seen it done as 01-00, with "00" being treated as 100, not 0.

Doesn't matter, as long as it's consistent within a game.