A number of users have experienced connection issues with Magic Duels on apple devices. Here are some suggestions that might help:
- Check and make sure you're using the latest version of iOS.
- Try closing the game, removing it from memory and re-loading it. With most devices you can access this by clicking the home button twice. Then, swipe the game app to remove it from memory, and re-open.
- Try logging out of gamecenter, then back in.
- If you are trying to connect via a cellular network, try connecting via wi-fi instead. Slow or poor cell reception can prevent you from logging into the server.