Turtling is an uncommon move, seen mostly by inexperienced players trying to execute a butterfly. Turtling has been proven to be so effective that it overwhelms the target and kills them in a matter of seconds. For these reasons, players who "turtle" are seen as an inexperienced player wanting an "easy kill" rather than a fair fight because the latter would most likely result in their defeat. Henceforth, any player who performs turtling will often be called a noob and will be persecuted by the other players, being kicked out of the room at a whim.
Despite clearly being labeled a "cheap move," one would actually be surprised of the frequency of its use by experienced players. Players often turtle when they make a mistake in executing a butterfly, choosing to turtle to cover up their mistake. Since in the heat of battle turtling is often not noticed, it is used to back up their other moves. Turtling is often used in areas where it is crowded. Since nobody will essentially notice their turtling, they usually end up in the middle of the crowd dealing high damage to all others. Turtling is not useful for quests, because of the sheer number of the monsters. They usually gang up on the players and in this case (goblins attacking from all directions) turtling means that you are stuck in the spot, and on the contrary butterfly offers continuous movement, so it is good in a one on one battle or if monsters/players are teaming up on you.