NX is virtual currency used in all games serviced by Nexon America, Inc. NX can be spent to purchase in-game items, accessories, and services.
There are two types of NX:
NX Prepaid: NX Prepaid is purchased using Karma Koin, Nexon Game Cards, Xsolla, or PaySafeCard (PaySafeCard only available in Europe). There are no restrictions on NX Prepaid.
NX Credit: NX Credit is purchased using a credit card, PayPal, or Mobile charge. For security reasons, there are restrictions on how you can spend NX Credit. For example, items purchased with NX Credit cannot be sent to friends as gifts.
For MapleStory 2, NX can be used to purchase Merets: What are Merets?