PlayerSkillRating = 15 + 0 + 20 = 35;
ChanceToMake = (PlayerSkillRating / Item Skill Required To Make) * 100

Quality      Item Skill Required To Make
Bad          15
Low          15 * 2.5 = 37.5
Good         37.5 * 2.5 = 93.75
High         93.75 * 2.5 = 234.4
Great        234.4 * 2.5 = 586
Excellent    586 * 2.5 = 1465
Master       1465 * 5 = 7324.22
Perfect      7324.22 * 5 = 36621.1

Bad = 233%
Low = 93.3%
Good = 37.3%
High = 15%
Great = 6%
Excellent = 2.4%
Master = 0.5%
Perfect = 0.1%

OnSkillUse()
{
    var randNum = new Random();

    if((ChanceToMake / 100) != randNum)
        return "Failure";
    return "Success";
}