ZT Online is one of the most popular MMORPGs in China. It uses a free to play model and relies on the sale of premium digital goods to players for its business model. It is doing incredibly well, with revenues over $50m/qtr and EBITDA margins of over 70%. But it does so with a somewhat controversial game dynamic, focused on PvP (player vs. player) play (appealing mostly to Bartle’s “killer” player type), building animosity between players, and using this as a lever to sell increasingly powerful and expensive digital goods via a lottery like system of opening chests. Danwei posts an English translation of a Southern News (chinese language newspaper) story on ZT Online:

Good equipment means money. Unlike other games, in this game there are no items dropped when killing monsters or completing missions. “We all want the best,” said Lu Yang. “You have to go to the system’s shops to buy materials, and then use the system smith to make them. Or, you could go gambling.”

“Gambling” means “opening the treasure chest.” Gamers can buy keys and chests from the system for cheap: one yuan per set. When the key is applied to the chest, the screen will display a glittering chest opening. All kinds of materials and equipment spin inside the chest like the drums on a slot machine as the wheel of light spins. Where it stops indicates what you’ve won. Chests will frequently contain the high-class equipment that gamers desire, but the spinning light wheel always passes over them.

Lu Yang recalls that during her craziest period she was like a gambler in a casino. She would shout at the screen the name of the item she wanted, like “ebony, ebony,” or some high-class material, but ultimately she would obtain nothing but a pittance of experience. Ebony, or that powerful “ring of the nether world,” remained in the chest, gleaming seductively.

There is a “treasure chest” ranking in this world. Each day, the person who opens the most chests can obtain a power-multiplying “Sacred Stone for Mending Heaven.”

Via Raph, I saw Play No Evil’s breakdown of the ZT Online game dynamic summarized as

Gold Farming + RMT + Power-Leveling + PvP + Gambling = The Most Popular Game in China - ZT Online

Duels looks like it has taken a game design leaf out or ZT Online’s book, although it hasn’t yet introduced RMT(real money trade). Anyone building social games should read both the original story and Play No Evil’s analysis of game mechanics.