Summary:
If you are planning on becoming powerful in this game, you will need to memorize the element system.This guide is made by Nathanial Musin (aka neko2008).
This guide is quoted from PDO Forum, you can view the full version from it.
Introduction:
Well, to start out, let`s go over simple controls.
V = skills B = backpack C = character Q = quests M = map F = available titles and other statistics
F1-F12 and #1-9 can all be used as hotkeys for items and skills. You can also set a certain spells to the right click for the mouse. Click and hold the left click to move about. Left click monsters to target them. Double click to do a basic frontal assault. Hit a hotkey to use a skill. After learning the Leap skill, you can jump across rivers and other spaces by holding down Ctrl and left clicking the spot you desire to jump to.
When looking at the map, you can hold down the right click to move the map and see all the available areas.
The element system works off of a basic one element works well against another and poorly against yet another. There are 5 elements: wood, earth, water, metal, and fire.
Metal does more damage to Wood and less to Water. Water does more damage to Fire and less to Wood. Wood does more damage to Earth and less to Fire. Fire does more damage to Metal and less to Earth. Earth does more damage to Water and less to Metal.
If you are planning on becoming powerful in this game, you will need to memorize those 5 lines. It is not difficult to memorize them, but it is necessary to do so. Additionally, in order to gain new skills for your elements, there are 2 things you must do. First, you must fight monsters of your same element in order to gain elemental experience. It is elemental experience and character level that determine whether you are able to learn a skill, so finding monsters of your same element is important if you want to be able to learn more skills. Additional, you can go to the Elemental Fairy Realms (explained later in the guide) where you can find each Fairy Realm has only a certain element of monster. The other important thing to do is to hunt monsters whom you are weak against. Monsters will drop skill tomes of the element that is weak to them. So in order to find Fire tomes, you would have to hunt Water monsters. Finding the tomes is not easy, because their drop rates are low, but they are the only way to increase the power of your current skills and gain new skills for your element.