207
votes
Accepted
Rolling a D10 (0-9) for hitpoints. What do I get with a zero?
A zero on a d10 counts as 10.
This isn't clearly specified in the 5th edition rules, but is clearer in earlier editions of the game, and widely understood among long-time RPG players. However, we can ...
- 84k
201
votes
Accepted
Does microwaving a die significantly alter its balance?
It doesn't do anything.
As a chemist, I had to give this a try.
First, I started with a die that had a clear bias toward ~18, according to the saltwater test. The first picture is the initial drop ...
- 63.7k
101
votes
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Why do most people consider a "00" and a "0" on a percentile roll a 100?
In common practice a d100 is effectively a 0-99 roll, with the stipulation that 0 be treated as 100
The game needs a way to roll 1 to 100 with equal chances, and no chance of getting zero.
Let's ...
- 7,665
97
votes
Is there any known limit for how many dice RPG players are comfortable adding up?
So, I am a freelance game designer and I’ve worked on a couple of systems and with a couple of design teams, but I am a “professional” only in the strictest sense (I have been paid for my game design ...
- 357k
93
votes
Accepted
Player may be manipulating die rolls, but I'm uncertain. How do I approach the situation?
Use a Rolling Tray
I don't want to accuse someone of cheating if they were not, but I
also don't want cheating to continue if it is in fact occurring
Since another player has already mentioned ...
- 144k
90
votes
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What dice mechanic gives a bell curve distribution that narrows and increases mean as skill increases?
(SKILL+CONSTANT) dX, keep highest CONSTANT
I don't know exactly the behavior you're going for, so there'll be a few arbitrary numbers in my example:
skills can be ranked from 0 to 5
dice rolled are ...
- 102k
84
votes
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How to approximate rolls for potions of healing using only d6's?
Let's not overcomplicate it: a simple Nd6 + X formula will work just fine.
Specifically, the effects of Greater (4d4 + 4) and Superior (8d4 + 8) healing potions are quite closely replicated by ...
- 24.5k
82
votes
Accepted
What is the difference between rolling more dice versus fewer dice?
From what I can gather what you're asking, you want to know the probabilistic difference between rolling 10d10 and 5d20. You've rightly pointed out that each roll has the same maximum and that each ...
- 18.7k
80
votes
Rolling a D10 (0-9) for hitpoints. What do I get with a zero?
You are correct. Many old school d10s are marked 0-9 but you count the 0 as 10.
If he doesn’t listen to reason, next level use one of the d10s marked 00-90 instead and demand your 45 or so hit ...
- 176k
69
votes
Accepted
What does dice notation like "1d-4" or "1d-2" mean?
GURPS uses 6-side dice for practically everything. It's more economical to refer to them as simply "d" rather than "d6."
GURPS uses six-sided dice only […] GURPS uses the "...
- 29.3k
67
votes
Accepted
Is it possible to emulate common polyhedral dice rolls using just a d6, and if so, how?
It's pretty trivial if you allow occasional discarding of rolls/rerolls.
d2 (gonna need this later): if result is odd, read as a 1. If result is even, read as a 0.
d4: discard any results of 5 or 6.*
...
- 102k
66
votes
Accepted
Dice Rolling Method Fairness
This is a classic clustering fallacy
Wikipedia defines the clustering fallacy as:
...the tendency to erroneously consider the inevitable "streaks" or "clusters" arising in small samples from ...
- 63.7k
66
votes
Simulating these special dice on more regular dice
Look at the pips a certain way
Tell your kids that the pips on the dice represent where you hit. A pip in the center means that you hit on-target, a pip on the sides means that you missed.
As special ...
- 1,671
65
votes
How to let my players fail their rolls intentionally, but covertly?
You might want to take some inspiration from the game Paranoia.* In particular, instead of trying to avoid hidden notes, make note-passing between the GM and players a common and ubiquitous mechanic ...
- 24.5k
62
votes
Player may be manipulating die rolls, but I'm uncertain. How do I approach the situation?
Talk to your players
Seriously. This is the very first step. Do not accuse anyone, just talk. There may be many reasons for cheating on dice:
Failed roll ruined otherwise good plan that had 90% ...
- 26.1k
60
votes
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Help me identify these 20-sided dice with assorted numbers from 4 to 72
I went and Googled for the numbers, and the first (and currently only) result was US patent 7815191B2 titled "Equals: the game of strategy for the basic facts". The abstract reads:
"...
- 24.5k
57
votes
Can a Circle of the Stars Druid roll a natural d3 (or other odd-sided die) to bias their Cosmic Omen roll?
The rules assume you only have a standard polyhedral set.
It seems abundantly clear to me that the intent is for the die to have an even numbers of sides. The feature’s outcomes are based on odd or ...
- 153k
56
votes
Accepted
Is there a name for this 20 sided die with two 1s, two 2s, etc?
Gamescience, a dice manufacturer, calls such a die simply a d20 0–9 Twice. Yours appears to be this one, and, as of this writing, it appears you can buy more.
However, you may not need to. The owner ...
- 192k
55
votes
Accepted
Is GameScience's non-cylindrical seven-sided die a balanced/fair die?
The real experiment is difficult
The linked dice in the question are out of stock, so only people who already have a lot of these dice and are willing to do the statistical tests can give the "...
- 63.7k
54
votes
Is it stated in the rules to be standard practice to hide rolls in 3.5e?
DM Lies and Fudging rolls
To begin I want to cover the idea of fudging a roll. It may be considered controversial and all to many people, but it's both advised and explained in the 3.5e DMG on page ...
- 2,206
53
votes
Accepted
What are the odds of rolling high all the time?
This may not be as unlikely as you think
Preamble: Probability is Hard
So distributions like this are tricky, because a lot of people assume, wrongly, that they only need to calculate the odds of ...
- 52.9k
48
votes
Accepted
How to let my players fail their rolls intentionally, but covertly?
Secret Rolls
You could simply ask that the players roll all of their checks in secret, then tell the other players the result. The success of a lie depends on the player's bluffing skills. You can ...
- 8,989
48
votes
Is GameScience's non-cylindrical seven-sided die a balanced/fair die?
No
(With 99.5% Confidence)
I purchased 5 of these dice to test their fairness. I rolled the dice 2250 times (450 sets), by hand in the dice bowl pictured above, and recorded the results.
Face
Count
...
- 1,570
47
votes
Simulating these special dice on more regular dice
Map the answers to the face of a 6-sided die
There are exactly 6 faces listed for your dice. They can thus be replaced by any fair six sided die by creating a translation table such as:
$$
\begin{...
- 34.9k
47
votes
How to make a device to randomly choose one of three possibilities, with caveat that sometimes one of them is not available?
In general, a deck of cards is useful to select a choice from a menu that excludes prior choices.
In this particular case, choose three playing cards to represent the monster's possible actions. On ...
- 4,657
46
votes
Why do most people consider a "00" and a "0" on a percentile roll a 100?
That method of rolling percentile dice actually pre-dates D&D.
Reading percentile dice in this manner pre-dates D&D, and has been used consistently in the rules throughout editions of the ...
- 84k
45
votes
A player rolls several 20-sided dice, takes the lowest value, ignores the rest. What is the probability of this value being at least 7?
AnyDice is straight forward for this
If you want to save yourself going through the maths, AnyDice will solve this for you.
While doing more complex things can get tricky (up to not possible), it's ...
- 48.8k
45
votes
Accepted
What is a decent dice rolling strategy for partial/half advantage?
The most straightforward way to add "half Advantage" is to only make it work half of the time. You can do this by using different colored D20s and throw in another d6 to decide whether you'...
- 82.1k
45
votes
How to make a device to randomly choose one of three possibilities, with caveat that sometimes one of them is not available?
Use a d6 with a reference table
In the following table, the main entry is the attack assuming the monster is free to choose from among all its attacks. The parenthetical entry is the attack used only ...
- 56.8k
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