he following chart shows how experience and drops are influenced by the difference in base level between you and the monster. For example, if you are killing a monster 10 levels higher than you, you would receive 140% experience and 100% drops.
This chart only applies to iRO, which uses adjusted settings for drop rates. However, as of May 2011, iRO has removed all drop penalties for all level ranges. It is unknown if any drop penalties will be re-added at a later date.