//Title: Probability Function
//Credit to: Jtgibson
//Contributed by: Jtgibson

//Original idea from Angband/ZAngband

//This simple macro generates a probability roll based on a
// ratio of "one in [chance]".  For example, a 1 in a million
// chance is described as ONE_IN_(1000000).

//This is very useful in if() statements.  ONE_IN_(X) returns
// 1 if the roll is successful and 0 otherwise.  Thus,
// if(ONE_IN_(1000)) will return true (on average) 0.1% of the
// time.

#define ONE_IN_(X) (!rand(0,(X)-1))


///*
//Testing code/sample implementation:

mob/verb/test_one_in()
    usr << "Rolling a one in three chance:"
    if(ONE_IN_(3))
        usr << "SUCCESS!"
    else
        usr << "Failure."
//*/