Questions tagged [statistics]

Statistics deals with the mathematics of probability-based games. This tag should be used for questions about tabletop game mathematics that relate to mechanics rather than game elements such as skills or attributes, and have relevance to RPGs in particular.

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Statistically, which is more of a severe penalty on a d20 roll, Disadvantage or a -10 penalty?

As a DM, I sometimes rule that a player can roll at Disadvantage or with a -10 penalty on a d20 roll. However, I've not been particularly consistent with this as I don't know what is a bigger ...
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Help with counting successes with multiple target numbers

I was trying to do an analysis of counting successes using AnyDice, and the basic version of it I got without problems. However, the system I am trying to investigate uses a mix of target numbers for ...
854 views

Help with "Roll XD12, and keep each middle dice as an individual result"

I've been playing with the idea of using 3d12, keep the middle, for skills rolls in my skirmishes (sort of simulating the curve of a 3d6 roll). But now I what to play with the idea of folding multiple ...
2k views

Looked at a different rolling (3d6, 3d6, average) for D&D characters in AnyDice and the result didn't come out as expected. What am I missing?

One of the historical dice mechanics in AD&D that can be used is: 3d6 twice for each attribute and pick the best of each pair of rolls. Normal 3d6 once gives a mean of 10.50. Rolling two sets of ...
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How to plot multiple dice pool series in AnyDice

I would like to draw a graph of this in AnyDice: y-axis: percentage chance of success x-axis: number of D6 dice in the range 1-10 series a: success is at least one 4+ series b: success is at least ...
200 views

Successive, conditional opposed rolls (anydice)

I am trying to model some probabilities for a pretty basic tabletop RPG mechanic. I have been searching for two days and trying to make this work myself, but my function-fu is weak, so I seek the aid ...
795 views

How can I calculate 'advantage' and 'disadvantage' when multiple dice are included. For example: the highest 2 of 3d10 the lowest 3 out of 5d6 I'm looking for a general formula, so that I can ...
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How to simulate d616 on Anydice?

In Marvel Multiverse Role-Playing Game, the players roll d616. It means that they roll 3d6, but: One die has a different color, its 1 counts as a 6 and it's called the Marvel die, which would mean <...
176 views

AnyDice - Complicated Stat Distribution

I'm trying to model average stat distributions for characters based on what a friend sent me: Balanced Stat Roll Roll 4d6 drop lowest five times. Count them together and deduct the total from 72. The ...
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What is the chance of rolling at least 10 before a 1 on a d20?

I need at least a 10 on a d20. I can roll until I get it, or I get a 1. What is the chance I succeed? I would like to have the general formula, not just for 10. The chance of success on the first try ...
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How does the odds of rolling at least 1 success change if Skill Grid nodes change from "+2 TN" to "+1 TN -1 Dice"?

The skill tree is brutal. For those who don't know, In Shadowrun 2nd edition, you can use skills you don't have by defaulting it from a skill or attribute you have by moving through the diagram shown ...
286 views

Count successes in pools of stepped dice

I tried to find this but my google-fu fails me. This is a mechanic similar to Blade Runner or Twilight 2000 RPG. For any action, the player rolls 2 dice which could range from 2d6 to 2d12 or anything ...
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Is "1d10 rerolling 1&2" equivalent to "1d8+2"?

Good old Cyberpunk 2020, 2nd edition, 2nd printing, offers two versions of rolling for statistics to players because point-Buy without rolling is for referees only. They read: Random: Roll 9d10 and ...
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Help with AnyDice for custom system

Can someone please provide guidance on how to make my system work within AnyDice? The gist is: player stats dictate how many dice in a pool of d8s are rolled, if they have gear or skills proficiencies,...
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Is a Superficial wound actually worse than a Light wound?

An interesting detail of Burning Wheel (Gold Revised) tests is that (unlike some other TTRPG systems) the exponent and the obstacle number are not "symmetric", in the sense that (say) a B4 ...
149 views

Anydice help with irregular dice pool [duplicate]

Here's the gist of it: I roll a number of different size die like 2d6, 2d8 and 1d12, looking for the highest die. I found a nifty Anydice program that helped me understand the probabilities like this. ...
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How can you calculate the likelihood of getting a set of stats or better when rolling 4d6 drop lowest?

If I have a given set of character stats from rolling with "4d6, drop lowest", how can I calculate the probability of getting that specific result, or better values for each of them? For ...
110 views

Anydice: Number of successes when dice can be boosted

Trying to run some statistics on anydice and I'm getting an odd result. Figure something must be wrong with my code but I can't find it. My situation is this: Player rolls 4d6 and drops lowest. They ...
834 views

Recursive combined probability for triggering a bonus attack?

I'm trying to determine the average damage per round for a homebrew fighting style, so that I can compare it to other types of combat choices, and see if thing will remain balanced, when we introduce ...
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How do I calculate the probability for a critical hit, with an expanded critical range, and advantage/disadvantage?

I know the critical hit probability for normal critical range (natural 20) is: normal: 0.05 advantage: 0.0975 disadvantage: 0.0025 But I don't know how to actually calculate this, and consequently, ...
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1 vote
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How to include pushed roll chances in anydice?

D6 dice pool from 0 to 6 where resolving 0 is rolling 2 dice and counting the lower result only. Rolling 5 or 6 means a hit. Rolling 1 is a mishap. Degrees of Success: Failure: no hits at all Mixed ...
1 vote
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How does success chance change when a certain die result counts as multiple partial successes?

Dice mechanism: count wins (> 4) of [Mod]d6 (AnyDice). Mod ranges from 1 to 10. Difficulty ranges from 1-10, 1 being trivial, 3 being moderate, 5 being difficult, and 6-10 being ever increasingly ...
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How can I simulate decreasing randomness even though randomness is increasing?

I am seeking a way to decrease variance as character skill advances. I've considered various mechanisms for dice tests. I have one in particular that does not accomplish this by default, but I like ...
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Over time, how does doubling dice on a crit compare vs having another action? [closed]

Basic 5e rules for crits say that you double the values rolled on dice. I'm playing with a homebrew idea where instead of doubling the damage dice you instead get another action, which can also crit. ...
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Part II of a probability problem I am working on for a mechanism to move tokens on a chart. Part I was two D4 dice. Part II is much different! [closed]

For Part I of this discussion, see this thread: Probability help on rolling two D4 with all doubles counting as zero except double 4s, which count as 4 That dealt with probabilities using two D4 dice, ...
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Probability help on rolling two D4 with all doubles counting as zero except double 4s, which count as 4

So I have devised a game system involving two D4 being rolled to determine movement on a chart. It works by tabulating the difference between the dice pips on each die, e.g., Die 1=rolls '1' vs Die 2=...
1 vote
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How does this 2D6 probability math make sense?

I have a question about understanding the math to a previous question I had posed (answered successfully). Link at the bottom. The question is how does it make sense that rolling a 2D6 Die consisting ...
226 views

Using AnyDice.com to calculate Non traditional dice combinations

I am not learned enough to figure this out alone. Not yet at least. I am trying to figure out how to use anydice.com to get probabilities of two different situations with dice. The main question is ...
1 vote
263 views

Producing a similar distribution to 4d6k3 but for the range [-4, 4]

I'm making a fork of D&D 5e (based on the SRD but then customized) and one of the changes I'm making is removing the whole score/modifier distinction and just going with a simple "score == ...
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1 vote
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Help With Trophy Dark and Trophy Dark Risk Roll Probabilities

Has anyone done some basic probabilities on the Risk Roll from Trophy Dark or Trophy Gold? This level of statistics is well beyond my knowledge. Risk Roll A player will build two D6 dice pools. One ...
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Anydice - Roll a d20 under target number but beat an opposed die

Curious about the following Anydice formula. I’d like to know how to calculate what it would look like to roll a d20 UNDER a specific target number (lets say 14 or 10), but also have that d20 still ...
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490 views

Is it possible to combine multiple outputs in AnyDice?

I have a situation where I will be making four attacks that do different amounts of damage over the course of a round. I have the average damage of each of them(including the likelihood of missing ...
1k views

How do I calculate probability for the dice mechanic in my custom indie ttrpg?

I am currently working on writing an indie TTRPG based on the "press your luck" style games instead of being based around miniature war games. I am struggling to understand the probabilities ...
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AnyDice: Limited exploding dice

I'm trying to write a custom explode function, which has a limit on the number of rerolls available. A basic limit of limiting the number of rerolls per die is easy enough. The problem is trying to ...
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How to calculate the probability to roll a specific pattern with Y dice and Z rerolls?

I'm working on a dice-heavy RPG, and trying to model a generic AnyDice function to calculate the probability of rolling a specific desired result for dice faces, such as "At least 3 dice with ...
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AnyDice function to reroll one die if any die rolls X

I’m by no stretch of the imagination any sort of programming type, but I’ve been trying to use AnyDice to rank all the possible ways the die rolls can be modified in the board game HeroQuest. The ...
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How can I map a single d20 to a number of hits? (use case: Animate Objects)

The Problem Suppose we have a character using Animate Objects (D&D 5e) to animate 10 Tiny objects, and is attacking the same enemy with all of them. According to RAW, you'd make a separate attack ...
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Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers)

I'm trying to generate a complex probability table for a dice pool with between 1--14 D6. The table will contain the probability of success and of critical failure, given a number of D6 rolled and a ...
815 views

How does one Calculate Dual Variable Probability?

Or asked another way: How do we determine the probability of given grapple to succeed? In DnD 3.5 the grapple mechanic relies on double variable randomness in order to determine success or failure. ...
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What is the average difference between AC and Touch AC for monsters?

Or asked another way - How much easier is it (typically) for a player to hit touch AC rather than regular AC? This is a supporting question for: Is it a viable tactic to use a flurry of blows monk to ...
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841 views

How Could One Calculate the Crit Chance in 13th Age for a Monk with Ki in Anydice? (If It Is At All Possible)

In 13th Age a critical is achieved when you roll a natural 20 on a d20. The Monk class has a few features that can fundamentally change its potential to crit. First off, a Monk using bare hands to ...
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I need a 'standard array' for a D&D-like homebrew game, but anydice chokes - how to proceed?

So, I'm working on a homebrew RPG that is similar to several FRPs that use 3d6 sorts of starting values for attributes/characteristics. I know how to calculate the standard D&D (5E or other) '...
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When does Polearm Master deal more damage than an ASI?

Would a fighter deal more expected damage by picking the Polearm Master feat at any point before they maxed their Strength, or is it better to first always increase your Strength in terms of damage? ...
246 views

AnyDice: Count successes plus a limited number of easier successes

I've been searching around but haven't yet found how to get this average out of AnyDice. Players roll a pool of d6s. Normally, a success is counted on a 4, 5, or 6. However, there's a condition a ...
3k views

How many rolls of a D20 would you expect to equal or beat (20 - number of tries)?

I have what is chiefly a probability / game-design query, but one with a clear RPG gaming purpose behind it. Assume I have a check in some game system, using a single 20-sided dice, that requires ...
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In Unearthed Arcana: Expert Classes, changes were made to the Great Weapon Master feat. How does this affect the damage output of Great Weapon Users?

On September 29th, 2022, Playtest material for OneD&D was released for the Expert Class Groups, and included in this unearthed arcana were some planned feats for the new version of Dungeons and ...
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Statistically, when should you wait to use Sneak Attack on a second attack with advantage?

Assume you have a Fighter/Rogue with one Extra Attack and attack advantage. Your first attack hits, but doesn't crit. Should you apply Sneak Attack, or save it for the second attack which may crit but ...
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How often do I need to sing Happy Birthday to myself to survive Space Junk Cyberpunk?

In Space Junk Cyberpunk I can sing Happy Birthday after every third roll to remove one loneliness. Here are the rules: You have three scores: BREAKDOWN (which starts at 0) LONELINESS (which starts ...
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