#1
In Splinterlands, cards are “leveled up” in only one way: by combining multiple cards into a higher level card.
Cards have a Base Card eXperience, or BCX, which represents how many cards have been combined into that one card. As an example, when two 1 BCX cards are combined, the result is a single 2 BCX card.
The number of cards needed for each level can be seen on the Stats of the card, under the Cards header. This values are cumulative, i.e. a Level 2 Kobold Miner requires 3 BCX, or 3 Level 1 cards. However, to reach Level 3 it requires 5 BCX, so that Level 2 card will only require 2 additional Level 1 cards to level up once again.
Combining cannot be undone, and as cards are leveled up, the total supply of that card is always reduced.
NOTE : Please make sure that you buy summoner cards because a level one summoner cannot fully utilize a leveled up monster. Splinterlands.wiki https://splinterlands.com?ref=hunterfly