MapleStory/Quests/GM Events

Occasionally, but particularly around each version's Anniversary event, Game Masters (GMs) will host special GM events. These events are typically announced by the GM that is hosting the event about 10 to 15 minutes in advance. These events take place in Lith Harbor, Orbis, Ludibrium, or, very rarely, Southperry of Maple Island. These events only occur on one channel at a time, and can only be participated in once every 24 hours. There are numerous different types of events, both in teams or direct Player Versus Player competitions. The GM stands next to a special Event NPC which, when the event starts, players must click on to get in. A limited number of players can get in at one time. The GM will then enter the event map and start the contest. Once the contest starts, every player present receives an Event Trophy, a rare item only obtainable via GM events. When GM events are completed, each player who successfully finishes will receive a Scroll Of Secrets which, after a drawn-out quest, will result in a random prize.
http://strategywiki.org/wiki/MapleStory/Quests/GM_Events