To save your account, you can go to the "Data Transfer Settings" from the Gear icon when you are in-game, then choose "Data Transfer with KONAMI ID". Register a new account if you don't have it yet and bind it to the account.
June 7th update
Recently, there were problems associated with making a KONAMI ID, which has now been fixed, but a new method to save your account is now added as well. You can now set up a data transfer to back up your account using Google Play Games. Simply log in to your Google Play account when you are in-game, and choose "Data Transfer Setup (Google Play Games)" in the Data Transfer Settings.
Setting up a data transfer
1. Tap a gear-shaped icon
2. Tap "Data Transfer Settings"
3. KONAMI ID or Google Play Games
You can link your game data to both a KONAMI ID, or Google Play Games. In case one of them isn't available, you can use the other to restore your data. You can link your game data to a different KONAMI ID, or Google Play Games if you accidentally used a different or wrong account, but it will replace the previous one. If you plan on transferring from using Google Play services to iTunes, make sure you use KONAMI ID instead.
3.5 KONAMI ID
If you are using KONAMI ID, login or generate first before linking your game data to it.
If you did everything correctly, your account is now saved so you don't have to worry about losing it if your phone is broken, a data error or if you uninstall the game. You will have to re-download all of the data files though.
Using your account on a different device
When you want to use your account on a different device, you will need to log in to your account. When you first launch the game, before you tap "INITIATE LINK!", tap the button below for "Data Transfer" and log into your account.
If you set up using a KONAMI ID, simply log in to your registered account that you linked your game data to. If you are using Google Play Services, make sure you are logged in to the right account.
If you lost your account before you managed set up a data transfer, you can try recovering it from the "Contact Us" and "Submit Player Data Recovery Inquiry" from the gear icon in-game.
1. Tap a gear-shaped icon
2. Tap "Contact Us"
3. Read through the description & Tap the button
4. Submit inquiry
You will need to provide your information as accurately as possible for them to be able to identify that it is yours. Simply giving them your player ID is not enough, since anyone can look that up and is not a very reliable information. Try to remember stuff like deck names, latest card obtained of certain rarity or what device you used it on.
Next step is to wait patiently and check your email for a reply from their support team.
After i clickd the daily card reward event, i get the error prompt telling me to restart game if error still persist. I deleted and redownload game and it is still like that. Is this a glitch? Help! Thanks!
My Phone was literally stolen from me whilst i was texting my friend by 2 guys on a moped so i lost everything they drove up to me and stanched it out of my hand and drove off i cant remember my duelist id but i have written a ticket with everything i can remember that i was doing last
does this really happen to people? snatched? never has this kind of thing done to me, bc I rarely use gadgets when out in public areas or main (crowded) streets. U must be stupid, did you loosen your grip on your phone, why would it be taken away if you are holding into it? I can't understand.
dmbecher! 14days ago
A week ago my mobile phone deleted all my files by itself. Because I'm stupid I didn't use the data transfer function. So I send an data recovery inquiry to konami. They replied that my account is ineligible for recovery. Unsure about this statement, I replied to their answer to get further information about the problem. Now they told me, that the data recovery conditions weren't met. I researched this, but every conditions I found I definitely met, so I wanted to know what condition exactly wasn't met. But knoami won't reply anymore. So I'm really unsure what to do know, cause I don't want to start over after spending around 300 hours on this game already. If someone has any idea or suggestion, I'd be really thankful for that.
I have successfully once completed the data transfer process previously and i was also able to recover it. But now i need to do it again because my phone needs a software update( i cant access the game data that's saved in my phone memory to move it to the external memory)... what i want to ask is if i do the process once again will i recover the data that i hold currently or will i only recover the data that i recovered previously when i did it( i've come too far from where i was since the last data transfer.)
P.s. i also don't know if moving the data from phone memory to external memory will work.
Just make yourself a google account and if you have it, transfer data to that. Just takes 2 seconds.
But to answer your question, once you've transferred, it saves automatically. In other words, once done, you're fine. At least, that's what I read here constantly. Hope that helps.