Dandân has never been a card that saw meaningful play in any traditional constructed format. Its restrictions are too narrow and its stats too fragile for competitive Magic: The Gathering, and that's exactly the point behind the format that eventually took its name.
Rather than trying to make Dandân good in a normal deck, Magic player Nick Floyd built an entirely new way to play around it back in 1996, one where the card's quirks become the whole game rather than a liability. That format is known as Dandân, or sometimes Forgetful Fish.
This guide explains how the format actually works, where it came from, and why it found new life nearly three decades after its creation.
Understanding the format is essential context for why Wizards eventually gave the card its own dedicated Secret Lair release, covered elsewhere in this series.
Dandân is a two-player casual format built around a single, pre-constructed 80-card deck that both players draw from and share completely, including the graveyard. Rather than each player bringing their own deck, both sit down to a communal pool of cards and fight over who gets to use them first.
That single shared resource pool is what separates Dandân from essentially every other constructed Magic format, where each player's deck is entirely their own from the first shuffle.
The format's two nicknames both describe its core cards directly. Ten copies of Dandân serve as the deck's only creatures and its sole win condition, giving the format the Fish half of its Forgetful Fish nickname.
Eight copies of Memory Lapse, a counterspell that puts a countered spell on top of its owner's library instead of the graveyard, supply the Forgetful half, since games frequently revolve around repeatedly bouncing the same spells back to the top of the shared library.
Players still start at 20 life with a seven-card opening hand and a maximum hand size of seven, keeping the format recognizably close to standard Magic rules. The key differences are structural: both players share one library and graveyard, the owner of a card on the stack or battlefield is whoever cast it, and mulligans are slightly more forgiving for hands with fewer than two lands or spells.
Simultaneous draws are also dealt one card at a time, starting with whoever's turn it is, a small but important rule for resolving situations where both players would otherwise draw from the shared library at once.
Because both players draw from and discard into the same zones, every card either player casts changes what's available to both of them for the rest of the game. Countering a spell with Memory Lapse doesn't remove it from the game the way it normally would; it just puts it back on top of a library both players are drawing from.
That dynamic creates long, grindy fights over card advantage and sequencing, since neither player can simply out-resource the other through raw card count the way a normal two-deck matchup allows.
For most of its history, Dandân stayed a genuine curiosity, known mainly to players who'd encountered it directly or read about it secondhand. That changed in 2023, when the YouTube channel Rhystic Studies covered the format, introducing it to a much wider casual Magic audience and sparking a wave of renewed community interest.
That renewed attention eventually caught Wizards of the Coast's own notice, leading directly to the Secret Lair Dandân Deck released through the Chaos Vault in March 2026.
Building a Dandân deck from scratch is straightforward, since the format's card list is well documented by the community and mostly composed of inexpensive mono-blue commons and uncommons, with Dandân itself being one of the pricier inclusions relative to the rest. Alternatively, the official Secret Lair Dandân Deck now offers a ready-built version with new artwork for players who'd rather buy in directly.
Either approach gets a table to the same core experience: two players, one shared library, and ten copies of a Fish that can't stop attacking once it's finally allowed to.
Magic player Nick Floyd, in 1996.
Two, sharing one library and graveyard.
Memory Lapse supplies the Forgetful half, and Dandân supplies the Fish half.
A 2023 Rhystic Studies video, followed by a 2026 Secret Lair release.
An 80-card shared library sees constant shuffling between two players over a long Dandân match. A plastic deck box keeps the whole shared library organized and ready to pass across the table.
Perfect Fit inner sleeves help protect frequently handled commons like Dandân and Memory Lapse through repeated games.
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