It freezes the client, causing a permanent lag on the client until it's un-frozen. Happens to everyone =\
So, I've noticed. I minimize MapleStory a lot, to browse the interwebs, HS, and such. When I get back into the game, it's as if I didn't even minimize. Everything is the same as it was before. Like if someone in my map killed everything, it would show what happened why I was gone. As if I "paused" Maple Story. Was wondering if this is on my part, or Nexons' part.
Sometimes the game will close out if you let it do that for too long, Saying you're "Speed hacking" So I wouldn't rely on that too much if you're doing it often.
Also > Go away from the game for a few minutes > Blaze wizard comes in and kills everything > open game > go deaf.
As a side note if you don't know, this doesn't happen in Windowed mode.