Normally quests were given by the People of the Earth, with the difficulty of the quest equal to the reward for completing it. The higher the difficulty, the greater the reward. For example, in order to get Dazaneg's Magic Bag, a player must complete a Level 45 Quest called Get the Magic Bag.
After the Catastrophe, the status quo changed with the People of the Earth no longer giving out quests, nor the Adventurers taking any quests due to the feelings of boredom and despair. After the Return of the Goblin King event, the Round Table Alliance began sending out goblin-hunting quests for players to complete, as well as show the People of the Earth that quests would be accepted again.
A worry veteran players have after the Catastrophe is the possibility of permanently losing a quest. Because quests are given by Landers, some Adventurers fear that if a quest-giver was to die or be killed his quest would also disappear, thus definitely preventing people from accomplishing it and earn its rewards.
- NHK's official Log Horizon website (nhk.or.jp)