A great evil has come across the land and it’s up to you to destroy this horrible evil. That pretty much sums up the story of the pre-made single player game.
Shattered Light comes with a World Builder that lets you create maps, write quests, create weapons, write NPC dialogue, and much more. Then when your world is full of quests and evil monsters to slay you can take it online with eight other people and, if you are the host, modify player attributes on the fly.