Forgetful fish, also known by its namesake card Dandân, is a fan-made Magic the Gathering format designed by Nick Floyd. It was originally designed in the late 1990s but became a popular format in the 2020s. Nick explains the rules, strategies and design process in a document Magic: Forgetful Fish
The format consists of an 80 card deck that is mono Blue control deck with 10 Dandân creatures and whole lot of sorceries and instants. Dandân is a 4/1 fish and it’s the only way to deal damage so essentially the game is played until 5 hits.
Players share a deck and a graveyard, making top deck management a key characteristic in the game. There are a lot of cards in the format that let you either manipulate the top deck (and by default, what your opponent is gonna draw) or draw cards if you don’t wish your opponent to get the card on the top of the library.
Many people have built their own variants of the deck, I use the one used by Loading Ready Run in their Friday Night Paper Fight episode (decklist). Since this variant plays Supplant Form that generates a Copy token, I’ve made custom Dandân tokens instead of using generic ones.
In addition to LRR’s episode on Dandân, I recommend watching Rhystic Studies’ Games within Games - History of “Forgetful Fish” as a starting point to understand the format’s history and main cards, Tolarian Community College’s Rhystic Studies and Dandân: A Blue Mage’s Dream | Shuffle Up and Play 50 and Cardmarket’s Dandân videos part 1 and part 2. In July 2026, Tolarian Community College released another video with Rhystic Studies and Josh Lee Kway.
Best part of Dandân in my opinion? It’s 80 cards so it fits into a small deck box, can be carried in the backpack everywhere and requires zero setup or deckbuilding to start playing. It’s like a pocket sized cousin of MTG Battle box in that sense, albeit with very different game play experience.
(I used Card Conjurer to create my custom tokens.)
I created a small, A7 size booklet to store with my Forgetful Fish. It has the rules and a full decklist: each card is listed with its mana cost, count and name (and in case of Mystic Retrieval, its Flashback cost).
I’m creating these paper rule/reference booklets (see MTG Battle box for its reference guide) because I want to avoid looking things up on a phone while playing card games with people or having to ask someone — potentially exposing your plans — details about cards or rules.
Multiplayer Dandân(dandan)
The wonderful people at Cardmarket’s Youtube channel introduced me to a 4-player variant.
They play a 100 card deck with otherwise regular multiplayer rules.
10 Dandân
2 Brainstorm
2 Code of Constraint
2 Council's Deliberation
2 Echoing Truth
2 Fortune's Favor
2 Founding the Third Path
2 Meat Locker / Drowned Diner
8 Memory Lapse
2 Metamorphose
2 Mission Briefing
2 Omen of the Sea
2 Opt
2 Predict
2 Preordain
2 Pulse of the Grid
2 Remand
2 Silundi Vision // Silundi Isle
2 Spreading Seas
2 Suspend
2 Swat Away
2 Thought Scour
2 Threads of Disloyalty
2 Truth or Tale
2 Unagi's Spray
2 Halimar Depths
2 Haunted Fengraf
14 Island
2 Lonely Sandbar
2 Mystic Sanctuary
2 Otawara, Soaring City
2 Quicksand
2 Shelldock Isle
2 Skyline Cascade
2 Soaring Seacliff
2 The Surgical Bay
2 Vesuva