public static void calcSkillMastery(L2Skill skill, L2Character cha)
    {
        //Skill id 330 for fighters, 331 for mages
        //Actually only GM can have 2 skill masteries, so let's make them more lucky ^^
        if(cha.getSkillLevel(331) > 0 && cha.calcStat(Stats.SKILLMASTERY_RATE, cha.getINT(), null, null) >= Rnd.get(10000) || cha.getSkillLevel(330) > 0 && cha.calcStat(Stats.SKILLMASTERY_RATE, cha.getSTR(), null, null) >= Rnd.get(10000))
        {
            //byte mastery level, 0 = no skill mastery, 1 = no reuseTime, 2 = buff duration*2
            byte masteryLevel;
            if(skill.isBuff() && skill.getAbnormalTime() > 0 || skill.isSongDance()) //Hope i didn't forget skills to multiply their time
                masteryLevel = 2;
            else
                masteryLevel = 1;

            if(masteryLevel > 0)
                cha.setSkillMastery(skill.getId(), masteryLevel);
        }
    }