2x Drop cards double the rate at which items can drop when you defeat a monster. So if an item normally has a 5% chance of dropping, there will be a 10% chance when you have a 2x Drop card equipped. A 2x Drop card can be purchased in the "Character Modifications" → "Drop Coupons" category of the Cash Shop.
When purchasing a 2x Drop card, please first take note of the effect the drop card has, as well as the activation times for the card. The activation time and the duration of the cards will be placed on the description of the card itself. Please make sure to read these descriptions before purchasing a 2x Drop card.
There are special four hour and one day 2x Drop cards available for a one-time use. As soon as the card is purchased, the 2x effect will activate for the next four hours or one day, respectively.
IN ORDER TO SEE THE EFFECTS OF 2X DROP, THE CARD MUST BE PLACED IN YOUR CHARACTER'S ITEM INVENTORY.
To transfer the item to your character, make sure to double-click on the 2x Drop card from the "Cash Inventory." The item will then be moved to the "Cash" tab of your item inventory. The 2x drop effect will only be active on the character the card is equipped on.
The 2x Drop cards purchased from the Cash Shop will not stack with one another, meaning that if you buy two 2x Drop cards, you will not experience 4x drop.
However, the cards will stack with certain 2x drop in-game events and with game functions that may also provide an increased drop rate. Not all in-game drop multiplier effects will stack, so please refer to the item description of the drop effect before attempting to purchase a 2x Drop card.