Players who are Lv. 150 or above in MapleStory can link their account to MapleStory M by inputting a special UserKey. Here's how to obtain your UserKey:
The code to link your MapleStory account to MapleStory M is available by logging in to MapleStory (PC). Once you've logged in using your Nexon account, travel to the Event Hall and speak to the Maple Administrator NPC.
Choose the "Talk to a Maple Admin" dialogue option and then select "Check Maple M Link String."
This will display the code that can then be entered into MapleStory M to link the accounts together.
***Additional information about the MapleStory M cross-over event is available on our website.