Every pack has 5 cards in it.

Slots 1, 2, 4 and 5 all come from what we’ll call “The Main Pool”, which consists of 78 cards with the same 7 rarity spread as the first two Rarity Collections had (Super Rare, Ultra Rare, Secret Rare, Collector’s Rare (Japanese Version), Ultimate Rare (Japanese Version), Platinum Secret Rare and Quarter Century Secret Rare). Certain cards in the Main Pool that have already been printed as Quarter Century Secret Rares, such as “Promethean Princess, Bestower of Flames”, are not printed as Quarter Century Secret Rare in this pack, but are printed with the foiling of the other six mentioned rarities.

The front card of each pack will always be a Super Rare.

The second card in each Pack is a Secret Rare with a 1 in 4 chance of being a Platinum Secret Rare or Quarter Century Secret Rare (i.e. a 1 in 8 chance for either).

However, the third card in each pack will come from the 200 card “Nostalgia Pool”. These cards only come in Platinum Secret Rare or Quarter Century Secret Rare. So far it seems to be once per box that it upgrades to Quarter Century Secret Rare.

The fourth and fifth cards are Ultra Rares with a 1 in 6 chance of being a Collector’s Rare or Ultimate Rare (i.e. a 1 in 12 chance for either).

This ultimately means that in a box of 24 packs you can expect (but aren’t guaranteed) roughly:

24 Super Rares
18 Secret Rares
3 Quarter Century Secret Rares
3 Platinum Secret Rares
40 Ultra Rares
4 Ultimate Rares
24 ‘Nostalgia’ cards

The Nostalgia Card is Platinum Secret Rare with a chance to be a Quarter Century Secret Rare, that based on current available data, currently appears to be one per box. Below is an included list of shown cards.