What are Zen? Edit
Zen is a special currency made exclusively for Perfect World games, including Jade Dynasty. Zen is purchased using real money and can be used to redeem special exclusive items at the Marketplace.
Currency Description and Exchange:
Zen = Perfect World currency; can be used in any PW game.
Jaden = Currency used in the Jade Dynasty Marketplace.
100 Zen = 1 gold Jaden
$1 USD = 1 gold Jaden
For example, to purchase a 20 gold Jaden item on the Marketplace (like a mount), you would pay $20 USD. This would get you 2000 Zen. Then, you transfer your Zen to your Jade Dynasty account and server. When you next log in (or switch realms), the Zen is available in the Marketplace as gold Jaden (20 Jaden).
How do I purchase Zen? Edit
Zen may be purchased on Perfect World's Website or it may be bought as a Prepaid Card at participating stores (such as Target in the USA)
Can I get Zen without Paying Real Money? Edit
Yes you can, by going to a Banker in-game. For more information on how to do this, please see this guide.