Last week, Wizards of the Coast revealed the Magic: the Gathering Mystery Booster at MagicFest Richmond, a new set described as a mix of "Chaos draft and Futuresight". There will be two versions of the Mystery Booster — a Convention Edition that will be available at MagicFests and conventions moving forward, and a WPN version that will be available starting March 13, 2020. Today, WotC has revealed more details about both versions of the Mystery Booster.
The Mystery Booster set is huge with a whopping 1,694 reprints and 121 copies of something new and surprising.
Each of the Convention Edition Mystery Booster pack will contain 15 cards: 14 from the huge main set, and one from that "something new and surprising" group that they're calling R&D Playtest cards, and if you want to know what they all do, check out the Release Notes and the full list of card names.
The WPN version will also include 15 cards: 14 from the main set and one of the 121 possible foil cards not found in the main set. Wizards also teased that the foil sheet has "some pretty exciting stuff". The whole list of possible foils will be revealed as we get closer to the March 13 release.
The Mystery Booster will contain cards in their original set symbols and numberings of one of their printings. What makes them different is the little Planeswalker symbol in the lower left corner, as shown here:
To make each draft experience unique, each of the 14 boosters slots from the main set of 1,694 cards has its own sheet of 121 possible cards, so it's likely that you could do an entire draft and not see the same card twice. Later this week, Senior Designer Gavin Verhey will release more information on each of the 14 slots and which cards are found in each slot in the main set.
You can check out the full list of Mystery Booster cards on Wizards of the Coast's website.