The Anatomy of: AAIE Dice Mechanics.
Check out the rest of the AAIE "Anatomy Of" series:
The series includes:
The Anatomy of Weapons.
AAIE "The town"
The anatomy of Balance.
The Anatomy of a Perk.
The Anatomy of an Ability
The Anatomy of AAIE Magic
Posting this to answer some questions that have come up lately , specifically about what are the "standard" difficulties in AAIE, which was asked at Metatopia this year of our lord 2017.
I figured the best way to answer that question would be to disgorge the die system in all it's fetid glory.
Try not to fall asleep this isn't the most exciting game stuff post ever..
AAIE is built around a concept of Bell Curves vs A straight distribution.
When I started this game I ripped the die mechanic form my table top skirmish game lovingly known as "The Block Game." Way back when I wrote the Block Game I decided that I didn't want a straight distribution of 5% per vlue that 1D20 provides. I wanted something that offered more options. More ways that the game could manipulate the chance of a characters attacks being successful. IN that effort I started looking at the distributions of rolling more than one die with one being designated an "Effect Die" to determine attack damage. I figured the success chances back then, when AAIE came around I just used the same methods..
Hold your breath lets do this:
At its base the game is this: For any normal action the player rolls 3D20 and looks at the middle value versus a difficulty to determine success.
For example:
If the player rolls three dice and they come up 12, 7, 16 the middle value is 12.
IF the player has disadvantage on the task they look at the lowest value in our example 7.
If the player has advantage they look at the highest value in our example 16.
Typical difficulties look like this:
Very Easy: 6
Easy: 8
Average: 11
Difficult: 13
Very Difficult: 16
The Game master lowers the difficulty of a task based on the attribute (if any) the character can use during the task. If lifting a log's difficulty is 11 and the players brawn is 4 the final difficulty will be 7. For the example character an average task is actually pretty easy.
Question: "Why does the GM do subtraction? That seems strange and kind of shitty."
Well yes it is. That brings us to the straight distribution portion of this dance.
The simple Answer is if the Difficulty falls to 1 or below the player doesn't have to roll to succeed they just do.
The complex answer involves the "Effect Die." The effect die is any one of your three D20 designated at the beginning of the game which determines how successful a successful roll is and how horrid a failed roll is.
Effect die:
Rolling a 16 or over on the effect die during a successful roll means the character can invoke perks, which are special effects that character skills or equipment can bring into the story.
Rolling low on the effect die during a success allows the GM (at their discretion) to interject complication into the character's success.
Rolling high on the effect die during a failure allows for the Gm to create partial success situations, where the character fails but still gets something done.
Rolling a 1 on the effect die during a failure creates a critical fail situation which is about as bad as it gets.
Remember the question a paragraph or two above?
If the difficulty is 1 or less the player only needs to roll the effect die. They automatically succeed but they still need to determine how strong a success they have scored.
So they roll 1d20 giving them a 25% chance to score at east one perk by rolling a 16 or better.
Which as you will see below is a solid 5% better chance of scoring at least one perk then the best chance a player can get on an average difficulty roll. In fact it's .70 % chance better than scoring a perk on a normal roll if the difficulty is only 2. Lastly it's still .02% better (WHOOPEE!) chance to score a perk even if the player has advantage on the roll and the difficulty is only 2.
In other words in it's mathematically in the players best interest to get the difficulty down to or less if they can.
The maths:
Here are how the difficulties stack up with disadvantage versus Normal versus Advantage.
The chart also shows the % harder a disadvantaged roll is vs a normal roll, and the % easier easier an advantaged roll is vs a normal roll at each difficulty tier.
What you want to look at here is the bottom graph which shows the % chance of the statement being "true" as in "did I roll over 11 and also over 15 on the effect die"
This tells me that if I have Advantage I have a 20.84% chance to be successful and score a perk.
On the other side of the scale if I have Disadvantage I have a 4.38% chance of failing vs a difficulty of 11 and also rolling a 1 on the effect die...probably causing my character to explode in a mushroom cloud of feathers and bile.
To wrap this up nicely the game die mechanic can be said to revolve around the base chances and how the player's actions / characters attributes stack up against challenges in the narrative environment.
The middle ground ... those base chances.
A normal roll vs an 11 difficulty the player has 50% chance of success or failure, an 10.63% chance of success with a perk, lastly a 2.5% chance of a critical failure.
So that's that a look under to hood at how how the dice in AAIE shake out. (HAr HAr)
I'm sure there have been some mistakes along the way.. I'm no statistician, Not even close. However if there are mistakes, I'm going to have to let them be because I built the mechanic on this foundation a long time ago.
WHEW .. That's a bunch.
Thank you for reading ..
-Mark
Check out the rest of the AAIE "Anatomy Of" series:
The series includes:
The Anatomy of Weapons.
AAIE "The town"
The anatomy of Balance.
The Anatomy of a Perk.
The Anatomy of an Ability
The Anatomy of AAIE Magic
All calculations done with "Any Dice" found here on the web. It's a great tool.
The series includes:
The Anatomy of Weapons.
AAIE "The town"
The anatomy of Balance.
The Anatomy of a Perk.
The Anatomy of an Ability
The Anatomy of AAIE Magic
Posting this to answer some questions that have come up lately , specifically about what are the "standard" difficulties in AAIE, which was asked at Metatopia this year of our lord 2017.
I figured the best way to answer that question would be to disgorge the die system in all it's fetid glory.
Try not to fall asleep this isn't the most exciting game stuff post ever..
AAIE is built around a concept of Bell Curves vs A straight distribution.
When I started this game I ripped the die mechanic form my table top skirmish game lovingly known as "The Block Game." Way back when I wrote the Block Game I decided that I didn't want a straight distribution of 5% per vlue that 1D20 provides. I wanted something that offered more options. More ways that the game could manipulate the chance of a characters attacks being successful. IN that effort I started looking at the distributions of rolling more than one die with one being designated an "Effect Die" to determine attack damage. I figured the success chances back then, when AAIE came around I just used the same methods..
Hold your breath lets do this:
At its base the game is this: For any normal action the player rolls 3D20 and looks at the middle value versus a difficulty to determine success.
For example:
If the player rolls three dice and they come up 12, 7, 16 the middle value is 12.
IF the player has disadvantage on the task they look at the lowest value in our example 7.
If the player has advantage they look at the highest value in our example 16.
Typical difficulties look like this:
Very Easy: 6
Easy: 8
Average: 11
Difficult: 13
Very Difficult: 16
The Game master lowers the difficulty of a task based on the attribute (if any) the character can use during the task. If lifting a log's difficulty is 11 and the players brawn is 4 the final difficulty will be 7. For the example character an average task is actually pretty easy.
Question: "Why does the GM do subtraction? That seems strange and kind of shitty."
Well yes it is. That brings us to the straight distribution portion of this dance.
The simple Answer is if the Difficulty falls to 1 or below the player doesn't have to roll to succeed they just do.
The complex answer involves the "Effect Die." The effect die is any one of your three D20 designated at the beginning of the game which determines how successful a successful roll is and how horrid a failed roll is.
Effect die:
Rolling a 16 or over on the effect die during a successful roll means the character can invoke perks, which are special effects that character skills or equipment can bring into the story.
Rolling low on the effect die during a success allows the GM (at their discretion) to interject complication into the character's success.
Rolling high on the effect die during a failure allows for the Gm to create partial success situations, where the character fails but still gets something done.
Rolling a 1 on the effect die during a failure creates a critical fail situation which is about as bad as it gets.
Remember the question a paragraph or two above?
If the difficulty is 1 or less the player only needs to roll the effect die. They automatically succeed but they still need to determine how strong a success they have scored.
So they roll 1d20 giving them a 25% chance to score at east one perk by rolling a 16 or better.
Which as you will see below is a solid 5% better chance of scoring at least one perk then the best chance a player can get on an average difficulty roll. In fact it's .70 % chance better than scoring a perk on a normal roll if the difficulty is only 2. Lastly it's still .02% better (WHOOPEE!) chance to score a perk even if the player has advantage on the roll and the difficulty is only 2.
In other words in it's mathematically in the players best interest to get the difficulty down to or less if they can.
The maths:
Here are how the difficulties stack up with disadvantage versus Normal versus Advantage.
The chart also shows the % harder a disadvantaged roll is vs a normal roll, and the % easier easier an advantaged roll is vs a normal roll at each difficulty tier.
Here is any dice figuring the Advantage distribution:
Here is the Normal roll distribution:
Here is the Disadvantage Roll Distribution.
So Using the same maths, I can figure out the chance to get a success vs a difficulty of 11 and roll over a 16 or better on one D20 to score a perk. ...
At the same time I'll look at what the chances of rolling a failure versus an 11 difficulty and also roll a 1 on a separate D20 (which is what is in effect happening when you designate one of the D20's as the "effect die."
This tells me that if I have Advantage I have a 20.84% chance to be successful and score a perk.
On the other side of the scale if I have Disadvantage I have a 4.38% chance of failing vs a difficulty of 11 and also rolling a 1 on the effect die...probably causing my character to explode in a mushroom cloud of feathers and bile.
To wrap this up nicely the game die mechanic can be said to revolve around the base chances and how the player's actions / characters attributes stack up against challenges in the narrative environment.
The middle ground ... those base chances.
A normal roll vs an 11 difficulty the player has 50% chance of success or failure, an 10.63% chance of success with a perk, lastly a 2.5% chance of a critical failure.
So that's that a look under to hood at how how the dice in AAIE shake out. (HAr HAr)
I'm sure there have been some mistakes along the way.. I'm no statistician, Not even close. However if there are mistakes, I'm going to have to let them be because I built the mechanic on this foundation a long time ago.
WHEW .. That's a bunch.
Thank you for reading ..
-Mark
Check out the rest of the AAIE "Anatomy Of" series:
The series includes:
The Anatomy of Weapons.
AAIE "The town"
The anatomy of Balance.
The Anatomy of a Perk.
The Anatomy of an Ability
The Anatomy of AAIE Magic
All calculations done with "Any Dice" found here on the web. It's a great tool.
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