In Summoner Master, there are five types of Rarity.
An Uncommon card is harder to find than a Common card. An Uncommon card is identified by having a green Version's symbol. In Dividing of 4 Kingdoms Version, An Uncommon card is identified by having a grey Version's symbol.
There is also a Secret Rare card, a Rare card which is extremely hard to find, in some Versions. They appears only one card per Version except Hymn of Exodus III (There are six Secret Rare cards in Hymn of Exodus III Version).
A Promo card can be found as a part of Wiser Magazine, a reward of a Tournament, or a card from an official trading campaign. This type appears in promotional Versions such as Treasure, and Celebration.