dice offers three basic methods for rolling dice:

dice.Roll()

,

dice.RollP()

, and

dice.RollD6()

The first function receives a single string parameter which describes the dice roll. For example, send 3d6 to roll three 6-sided dice, 1d20+1 to roll one 20-sided die and add 1 to the result, 1.5d6-1 to roll one and a half 6-sided rolls and subtract one from the result. Half-dice are taken to be a single die of half the normal faces. That is, 1.5d6-1 rolls one 6-sided die, one 3-sided die, and subtracts 1 from the sum of both dice.

The second function receives all the parameters of the dice roll separately (think of the P as "parameters", "pieces", or "parts"). The parameters are: number (the number of dice to roll), faces (how many sides, or faces, each die has), adder (any static quantity to add to the roll's total), and half (a boolean value indicating whether a half-die should be rolled in addition to the dice specified in the number parameter). The equivalent to dice.Roll("1.5d6-1") is dice.RollP(1,6,-1,true).

The third function receives a number and rolls that many 6-sided dice. The last rolled die is considered a "wild" die. A wild die coming up 6 causes an additional die to be rolled. This additional die is also a wild die, which means that if it comes up 6, the process continues, until a non-6 die is rolled.

All three functions return a DiceRoll object:

type DiceRoll struct {
    NumberOfDice int
    DieFaces     int
    Adder        int
    Half         bool
    Rolls        []int
    RawTotal     int
    Total        int
}

DiceRoll objects have a method Description() which returns a description like the one used to roll with dice.Roll().

Additionally, a throwdice runnable is included, which can take any number of dice roll descriptions as command-line arguments and prints the result for each. It will use the D6 system if passed the -d6 flag. It will also read from stdin if no command-line arguments are given, stopping on EOF or "exit" or "quit" (case insensitive). Note that in D6 mode, descriptions are merely numbers, specifically the number of 6-sided dice to roll.

(Yes, it's all very simple and not extremely useful... it's mostly an exercise on Go on my part.)