User blog comment:Usiar/Actual Gameplay Requirements for Ranked?/@comment-4022742-20130119141104/@comment-94.52.44.104-20130121124919

Late game, rune matter... if they are armor or magic penetration (esp since they're a limited amount of items that grant penetration and you can't buy htem all, at all times). You can get the squishy ap/adc to negative.