GM = Goblin Mine, an instance you can join once you reach lvl 50. it gives you shells, a currency used to buy armor pieces with good stats. then, the stats can then be extracted from the item. you will obtain a mana stone. this stone can then bu used to add the stats to any weapon/armor piece, up to a maximum or 6 stats / item.
SW = Siege War, an optional battle against another guild. the rewards are usefull : xp orbs, tp orbs, badges (used to obain new titles from a NPC in castle, these titles will give you some extra att points), and ressources for the guild. at low level, you can only extract crystal from the towers we own. it's boring but it helps a lot.
I did my best to awnser your questions, but english isn't my 1st language. If something isn't clear, tell me!
