Can I play while offline?
Dungeon lives on our computers, not yours. Whether you're using a MUD client or mobile device or our Web GUI, your computer has the controls but ours have the World. Think of it like a car. Your device is the steering wheel, but ours are the engine, body, tires, and everything else.
So yah, you have to be online. Your device and ours work together to create the experience.