BTS WORLD lets you manage your cards in a number of ways. One of them is to upgrade your cards, but this option doesn’t unlock until later in the game.
You’re going to need to upgrade cards eventually, though, so read on for the full guide on how to upgrade your cards (and why to upgrade them) in BTS WORLD!
It’s not immediately clear in the game why you should upgrade your cards, but in card management, it appears as an option. The reason is this: All of your cards have a level cap initially. Once you increase their level to level 30, they reach their maximum level.
The max level is the same for all cards of all rarities; however, if the card in question is a 3-stars or above card, then you’ll have the option to upgrade it, which will allow you to level it past 30.
Once you level a card to 30, you are able to keep the levels going, all the way up to level 50 maximum, but to do this, you’re going to need to upgrade your cards. Otherwise, the levels will remain capped out.
Once you hit the maximum level, the upgrade option becomes available, but first, you need upgrade stones. These materials appear mostly from the Exchange option. This allows you to exchange duplicate cards for upgrade stones for your specific band member.
The cards that you give up in the exchange have to be the exact same card. It can’t be the same band member in a different pose or with a different card rarity. The card has to be an exact duplicate in order for you to be able to exchange it.
That’s not the only way to earn upgrade stones; you can sometimes earn upgrade stones from one of the many quests, missions, achievements, and other reward-proving moments in the game.
Anyways, all that said, every character has their own upgrade stone. Get enough upgrade stones, and you’ll be able to upgrade the character using the upgrade button.
Once you do upgrade them, they’ll improve to a higher rarity. Once they reach said rarity, then you’ll be able to start dropping flowers, bouquets, and blossoms on them in order to level them up past 30. 50 is the maximum level for all of your upgraded cards.