Competitive guide
Prepare your Side Deck
like a Yu-Gi-Oh! pro
Siding is the art of swapping cards between your Main Deck and Side Deck between games in a match. Plan your IN/OUT patterns by matchup and by turn (1st or 2nd) directly in the deckbuilder.
Prepare my siding →What is siding in Yu-Gi-Oh!?
The Side Deck holds up to 15 cards that you can swap with cards from your Main Deck between games 2 and 3 of a tournament match. It is a crucial strategic phase in competitive play.
The goal is to replace cards that are less useful against a given archetype with targeted cards — specific Hand Traps, mass removal, or answers to their key mechanics.
The number of cards swapped must be exactly the same IN and OUT: if you bring in 3 cards, you take out 3.
Differences between going 1st and going 2nd
Going 1st — Playing first
- Goal: set up as many negations and interruptions as possible.
- Side IN: cards that complete your engine or add interruptions.
- Side OUT: Hand Traps (often useless going 1st), "going 2nd" cards.
- Examples IN: Dimensional Barrier, There Can Be Only One.
- Examples OUT: Nibiru, Evenly Matched, Lightning Storm.
Going 2nd — Playing second
- Goal: break the opponent's board and develop your own.
- Side IN: mass removal, monster negators, dis-enablers.
- Side OUT: slow cards or negations that only work going 1st.
- Examples IN: Evenly Matched, Dark Ruler No More, Kaijus.
- Examples OUT: Solemn Judgment, Infinite Impermanence (sometimes).
How to plan your siding with our tool?
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1
Create a pattern per matchup
In the "Siding" tab of the deckbuilder, click "+" to create a scenario. Name it after the opponent's archetype ("Vs. Branded", "Vs. Snake-Eye"…).
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2
Choose the turn
Switch between "1st" and "2nd" — each turn can have a different siding. This is often the case: you take out your Hand Traps going 1st but keep them going 2nd.
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3
Define IN cards
Select from your Side Deck the cards to bring into the Main Deck for this matchup.
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4
Define OUT cards
Select from your Main Deck the cards to take out. Verify that the number of IN = number of OUT.
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5
Review during the tournament
Open the Siding tab during your rounds to quickly check your plan and stop hesitating between games.
FAQ
Yu-Gi-Oh! Siding FAQ
From 0 to 15 cards. In competitive tournaments, a 15-card Side Deck is virtually mandatory — you need answers for all the important meta matchups.
Yes. After game 2, you can re-modify your deck (within the rules) for game 3. Your pattern can therefore evolve based on the result of the previous game.
Target the meta's mechanics: if opponent decks rely on the graveyard, play Macro Cosmos or Dimensional Fissure. If they use effect monsters on the field, Kaijus or Impermanences are effective.
There is no official limit on the number of cards swapped — but the number of cards taken out must equal the number brought in, and your deck must remain between 40 and 60 cards.
Glossary: competitive siding terms
Pattern
A precise IN/OUT card plan prepared in advance for a given matchup. Avoids hesitation between games in a tournament.
Tech card
A very targeted Side Deck card against a specific mechanic, often played at 1-2 copies. Ex: Imperial Order against Spell-heavy decks.
Floodgate
A card that prevents the opponent from playing normally. Powerful going 1st. Ex: Dimensional Barrier, Anti-Spell Fragrance.
Dés-enabler
A card that removes the opponent's combo centerpiece. Kaijus, Lava Golem. Bypasses special summon effects.
Which cards to side against the current meta?
Against Graveyard decks
Macro Cosmos, Dimensional Fissure, D.D. Crow, Bystial monsters.
Target decks that rely on the GY for their effects or summons.
Against combo decks
Nibiru the Primal Being, Dimension Shifter, Effect Veiler.
Disrupt their summon sequence before they establish their board.
Against control decks
Lightning Storm, Evenly Matched, Dark Ruler No More.
Break their established board going 2nd or prevent their negations going 1st.
Other available tools
Prepare your siding for the next tournament
Plan your IN/OUT patterns by matchup directly in the deckbuilder.