public void gainXP(int exp){
        _xp += exp;
        while (_xp > 100){
            _level++; //ding!
            _xp-=100;
            _health*=1.3;
            _damage*=1.3;
            _shield++;
            if (_level == 2) learnSkillOne();
            if (_level == 5) learnSkillTwo();
            if (_level == 10) learnSkillThree();
        }
    }