12 packs, each contains:

1 Foil-etched Mystical Archive rare or mythic rare – The only place to get foil-etched Mystical Archive cards is in the Collector Booster.

1 Foil-etched Mystical Archive uncommon – In this slot, you will always get one of the 18 Mystical Archive uncommons in a foil-etched treatment. This slot will be a 50% split between having the global Mystical Archive style and the Japanese variant.

1 Traditional foil Mystical Archive (global or Japanese alternate-art version) rare or mythic rare, borderless mythic rare, or extended-art rare or mythic rare – This slot is filled with all sorts of goodness!

1 Traditional foil Mystical Archive uncommon – There are 18 Mystical Archive uncommons, and each one can be found in this slot in traditional foil.

1 Extended-art rare or mythic rare, or a borderless mythic rare – In this slot you will get one of the Strixhaven: School of Mages extended-art rares or mythic rares from the main set, or a borderless planeswalker card, or a borderless mythic rare Elder Dragon (90 cards total).

1 Extended-art Commander (2021 Edition) rare or mythic rare – As noted above in the extended-art section, this slot will always contain one of the new Commander (2021 Edition) rares or mythic rares with extended art (80 cards).

1 Traditional foil Lesson – All 20 Lesson cards in Strixhaven can be found in this slot. 

1 Traditional foil rare or mythic rare – Most rare and mythic rares in the Strixhaven: School of Mages main set can be found here

2 Traditional foil uncommons – The uncommons that you can get here include the main set Strixhaven uncommons with the exception of the Lesson cards.

5 Traditional foil commons – The commons that you can get here include the main set Strixhaven commons and the common nonbasic lands (96 cards total). The common Lesson cards aren't included here as they are in the Lesson slot above.

1 Traditional foil token (double-sided) – The Collector Booster has the 7 different tokens that are created by cards in the main set as well as the two different emblems. Each token and emblem are found on one side of these double-sided foils. If you want to collect traditional foil tokens and emblems, the Collector Booster is the only place in Strixhaven that they can be found.