but what might work is that you give up two cards to pick one of your choice. this exchange is not made with other players, but the card "shop" . trading alone can be abused by multiple accounts, but if one of the trading accounts is always controlled by the site ( ie card shop) then it's unabuseable
wow are special challenges around more often than i thought? cos that jade lemon thing was around for less than 12 hrs i think, so have there been ones in the past i missed?
 "Kongai"){kind=icon}
 "Death vs. Monstars"){kind=icon}