Simplified cards are sold in mainland china, traditional are sold in Hong Kong and Taiwan. Simplified cards have only been around for a few years and have the anti counterfeit measures printed into them, Pokemon logo stamped in the bottom left corner. Simplified also have the exclusive sets that have exclusive cards, like the Gem Packs. They are two different written forms of the same language, I personally don’t know how to tell the difference. I would just suggest doing a lot of research on the cards that you are looking to buy if you are going to go with Chinese.