Generating random numbers

This lesson covers generating random numbers with VB.NET's Random class, with the aim of building things with a random element such as dice or rock-paper-scissors.

New Random() creates a generator and rnd.Next(min, max) gives a random integer in the range you specify. Use it wherever each run should differ — games, draws.

The sample code picks a dice roll from 1 to 6 with rnd.Next(1, 7) and one of Rock, Scissors, or Paper from an array with rnd.Next(0, choices.Length). Note that the second argument of Next() is exclusive.

A common early stumble is exactly that range. Next(1, 7) returns 1 up to but not including 7 — that is, 1 to 6 — and not knowing it leaves you with the wrong range.

In professional work, random number generation is used widely — item drops in a game, generating test data, sampling for verification.

📖 Reference code

Module Program
    Sub Main()
        Dim rnd As New Random()
        Dim dice As Integer = rnd.Next(1, 7)
        Console.WriteLine("Dice roll: " & dice)

        Dim choices() As String = {"Rock", "Scissors", "Paper"}
        Console.WriteLine("Rock-paper-scissors: " & choices(rnd.Next(0, choices.Length)))
    End Sub
End Module

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run VB.NET directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).