The Basics

AnyDice can perform mathematical operations on numbers, like any regular calculator can.

Addition: 1 + 2 yields 3.
Subtraction: 3 - 2 yields 1.
Multiplication: 2 * 3 yields 6.
Integer division: As AnyDice only supports whole numbers, all divisions are integer divisions, rounding toward zero. So 6 / 3 yields 2, while 5 / 3 yields 1.
Exponentiation: 2 ^ 3 yields 8.

AnyDice uses the traditional operator precedence. If performs all unary operations first (for example -3). After that, it does exponentiations, then multiplications and divisions, followed by additions and subtractions. It performs operations of the same precedence in the order it encounters them, from left to right. You can use parentheses to change order in which the operations are performed.

Comments

Any text enclosed with a backslash character on either end – \ like this \ – will be ignored by AnyDice. This is useful for writing explanations or for temporarily disabling some commands.

Variables

Variables are uppercase words, which may contain underscores. It is possible to assign something to a variable, so that you can reuse it later. Assigning something to a variable will replace its previous value.

X: 3

output X named "It's a 3!"
output X + 1 named "It's a 4!"

X: X * 2

output X named "It's a 6!"

Conditions

AnyDice allows you to compare two values, to check whether a certain condition is true. If so, the result will be a 1, otherwise a 0. Condition operations have a lower precedence than all mathematical operations.

Equal?: 2 = 2 yields 1, while 1 = 2 yields 0.
Not equal?: 1 != 2 yields 1, while 2 != 2 yields 0.
Smaller?: 1 < 2 yields 1, while 2 < 2 and 3 < 2 both yield 0.
Greater?: 3 > 2 yields 1, while 2 > 2 and 1 > 2 both yield 0.
At least?: 2 >= 2 and 3 >= 2 both yield 1, while 1 >= 2 yields 0.
At most?: 1 <= 2 and 2 <= 2 both yield 1, while 3 <= 2 yields 0.

Booleans

In general, the number 0 represents no while any other number – either positive or negative – represents yes. Using this logic, AnyDice allows you to perform boolean operations. This is useful if you like to check multiple conditions. Boolean operations have a lower precedence than all conditions, except for Not, which is a unary operation.

In the examples below, assume that the variable YES is set to any number other than 0, while NO is set to 0.

And also: YES & YES yields 1, while any other combination with a NO yields 0.
Or else: NO | NO yields 0, while any other combination with a YES yields 1.
Not: !YES yields 0, while !NO yields 1.