I only know how I can generate a random boolean value (true/false). The default probability is 50:50
But how can I generate a true false value with my own probability? L
You generate a random number up to 100 exclusive and see if it's less than a given percent. Example:
if(random.Next(100) < 40) { // will be true 40% of the time }
More generally, for a probability of X/Y, use an idiom like:
if(random.Next(Y) < X)