How To Dual Class
Upon reaching level 10 you will get a quest that tells you to seek out the class trainer in Varanas, a huge city. Once there you need to meet with an NPC in the Class Hall ( in game coordinates 56.9, 81.3). Be sure to read everything if you are still confused. One key point to bring home here is that you can not undo your secondary class. If you feel you have picked the wrong one, you simply have to start all over again with a different character.
So once you have decided on a secondary class, simply talk to the respective class NPC and viola
! If you still need more information on what each class does, the NPC will tell you a little bit more detail about them.
In order to utilize abilities from your secondary class, you first must 'change into' your secondary class. You can do this by visiting the class trainer NPC or simply by visiting your house, talking to your house maid (the NPC inside your house) and setting up the options there. Once the class options screen is pulled up, you can either change to the secondary class completely or start adventuring as a hybrid.
Primary Class vs. Secondary Class
Your primary class is the class that you currently are. If you started with a Knight and dual classed a Scout than your initial primary class would be Knight while your secondary class would be Scout. However, once you change your into your secondary class it will become your new primary class.
There are a few abilties that are class specific and can only be used if your current primary class is active. For example, a Priest has the ability to revive dead allies. The only way to revive the ally is if you are a priest and are currently using your Priest as your active primary class. While you are able to use a few abilties from your secondary class you can not use a class specific ability from your secondary class.
It still leaves a lot of flexibility though. A warrior that can heal himself/herself or a mage that can melee is all possible.
The Good, The Bad and The Ugly About Dual Class
Dual Classing in Runes of Magic allows players a lot of flexibility. However, it comes at a price. You see, as you gain experience through adventuring and questing your character gains both experience points and talent points (TP for short). Talent Points are used to increase the effectiveness of your abilities and spells. Experience is used to measure your level for whichever class is your primary class.
The TP gained for completing a quest or killing a creature will only apply to which ever class is active. So if you are dual classing as a Knight/Scout, you can only spend your TP to increase the abilities of your Knight. The same goes for experience gain. Once you start dual classing, your secondary class starts out at level 1. Therefore you basically have to start the grind all over again to make your secondary class more effective. So be sure to switch over and change into your secondary class throughout your adventures to take the full benefit of the dual class feature. All throughout the game you should typically strive to keep both your primary class and your secondary class around the same level.
The dual class feature can make your character much more effective in combat but it requires more time to take full advantage of it. Fortunately or unfortunately, dual classing is basically unavoidable in Runes of Magic. Choosing not to have a secondary class would result in a very weak character. Not only do you get 10% of the stats of your secondary class, but the extra abilities are always extremely useful. Whether you get heals, more damage, or just the ability to use attacks that utilize a different type of "mana pool" (like a knight who uses mana for knight attacks, and energy for rogue attacks), you will definitely need that secondary class.