Casino Randoms

You're request isn't very clear. However, suppose you have your own probability distribution for lifes:

lifes	probability	prob. density
1 - 99	50%	0.00505
100 - 199	49%	0.00490
200 - 200	1%	0.01005

Where third column holds discrete densities of probability
(note I've arbitrarly boosted number 200 density to make cumulative sum be 1, as required).

Now, if you extract a random number with uniform probability (as Random does) you've to equate the cumulative probability functions to get the corrensponding number of your distribution.
Since the granularity of our densities is 10^-5, we can choose the interval 0-99999 for Random and use only integer numbers, this way:

Random outcome	choosen life
0-504	1
505-1010	2
...	..
49490-49994	99
49995-50484	100
50485-50974	101
...	..
98505-98994	199
98995-99999	200

Implementing such logic is almost trivial:

public static int myNext(Random r)
{
    n = r.Next(100000);
    if (n < 49995)
    {
        return 1 + (n / 505);
    }
    else if (n < 98995)
    {
        return 100 + ((n - 49995) / 490);
    }
    else
    {
        return 200;
    }
}

:)