How do I re-roll?
Ceres M Guide
When starting your account, you go through the tutorial first before you're able to summon any troops. Once you've completed that section, you'll be awarded with an Ultimate Summon Ticket.
The Tutorial will bring you to the summon shop, and you'll be able to Open a Card Pack of 10 cards for free. Use this feature, and open your cards to see what you have. On the lower left hand side, there's a Resummon Button and you get to have 30 tries total for re-rolling.
What should I aim for when re-rolling?
Since you have 30 tries total, aim to get at least two troops who are 5 stars in their card. You should be able to tell it by the color of their card before you open them.
Silver Card = 3 Star
Gold Card = 4 Star
Purple Card = 5 Star
There are also classes in the game. Kings, Executor, Warrior, Mage, Hunter, and Elite. Troops from the King class are very good in the long run. These are the troops that are from this class:
What should I do if all 30 of my rolls aren't good?
It's better if you use a guest account first when you start. If you've used up all of your re-rolls, you can do the following steps to get a fresh one:
1. Open the arrow on the left hand side of the main menu, then click the Settings button.
2. Click the "Information" tab, then there's a reset guest feature there. If you're synced to a Gmail or Facebook account, you have to click "Withdrawal". Withdrawing an account however, will take 7 days to complete which is why having a guest account is better.
3. Create a new guest account, then go through the tutorial process once again, until you get to the free summons.