Within this TCG, there is a new Booster Series every three months (quarterly). Each Booster Series has at least 100 different cards, with rarities currently spanning from Normal (N), High Normal (HN), Rare (R), and Super Rare (SR). There are special rare cards depending on the Series which are listed below. The Promotional Cards for each Series are grouped together by Season.
The card ratios in Series 1-3 had a higher and lower number of Normal (48) and High Normal (24). From Series 4 onward, these numbers were balanced to 42 Normal and 30 High Normal, respectively with the exception of Series 17. Please visit the Series 17 page for more informational on that.
In each sealed Booster Box (16 packs), there is a guaranteed R+ and the off chance of having an SR+ or Secret Rare instead. From Series 5 onward, some
R+ and SR+ have different art than their normal R and SR cards. There are various types of Secret Rares like HNX, N+X, R+X, chibi +X, and Hero Rare (HR). The +X cards very similar to their normal cards, but some feature variant art, card borders, and some even have slightly altered skills like B09-034N+X Delthea.
Hero Rares were introduced in Series 18 as a type of secret rare that feature Main Characters like Lucina and Eirika. These cards are similar to R+ card styles and feature simpler skills which make them easy to use and play.