Video summary

The Art of the Side Deck in Modern Yu-Gi-Oh!

Main summary

Key takeaways

Educational

Main ideas / lessons about building a Yu-Gi-Oh! side deck

Purpose of the side deck

The side deck (15 cards) exists to:

  • Fix weaknesses and problems in your main deck
  • Improve your game plan for specific matchups, including being going first vs. going second

In best-of-three tournaments, you typically play about 2/3 of games post-side (most matches have 3 games, and 2 are post-side). Because of this, having a solid side strategy strongly affects match outcomes.

Side decking matters because you don’t just “have a deck”—you’re optimizing what changes between games.

Core mindset

Side decking is not linear; it’s iterative:

  • Evaluate matchups
  • Decide what to remove / add
  • Adjust card counts
  • Re-evaluate

Your main deck and side deck are linked:

  • Your main deck choices determine what you must side out
  • They also determine what gaps the side deck must cover

Start by identifying what you need to side for

Focus first on:

  • Which decks you expect to face
  • Categorizing them by how much you need to prepare

Deck categorization (a planning framework)

1) Category 1: Must-prepare (top meta decks)

  • Decks you should expect often
  • You want strong plans, sometimes including very specific answers

2) Category 2: Realistic but less frequent (tier-2 / less popular)

  • Decks you might face, but not constantly
  • You typically use more generic cards that cover multiple decks
  • Goal: prepare, but don’t waste excessive slots on hyper-specific tech

3) Category 3: Rogue / extremely unlikely

  • You likely face them once (or not at all)
  • You generally don’t build a dedicated counter plan
  • Instead, you rely on:
    • Side cards that incidentally hit them
    • Understanding the matchup so that if you draw into helpful cards, you can use them

Multi-purpose cards help (with a caution)

  • Cards like Nibiru, the Primal Being can be strong because they hit meta and some rogue decks.
  • But don’t over-prepare for every rogue deck—some rogue strategies are rogue for a reason.

Methodology: how many cards to side and how to choose them

Step 1: Determine what you will side out (going first vs. going second)

First, identify which main-deck cards are:

  • Bad in certain matchups
  • Bad in certain turn orders

General logic described:

  • Going first
    • Often side out more non-engine
    • Sometimes side out engine too, if necessary
  • Going second
    • You can often side out more engine
    • Rationale: extra draw reduces the chance you’re stuck with unplayable hands

The speaker’s example logic:

  • Going first: take out non-engine; keep engine to maintain consistency
  • Going second: remove some engine + non-engine that underperforms

Step 2: Estimate how many cards you can realistically change per matchup

You can’t side unlimited cards. In the example:

  • Going first: typically side in/out at least ~6 cards
  • Going second: more constrained (some key engine/utility pieces must stay)
  • Upper range described for going second: roughly 7–10 cards, depending on matchup type

Step 3: Decide side deck size allocation per matchup

Key factors:

  • Popularity of the opponent deck
    • More popular = more expected games = more “mileage” from those side slots
  • How bad the matchup is for you
    • Some matchups are already manageable with main-deck answers
    • If your main deck has strong tools, you may only need a few side cards
  • Your deck type (engine count & consistency)
    • Low-engine decks can side more because they don’t need many engine pieces
    • High-engine combo decks often can’t side out too many engine cards (they need multiple pieces to start)
    • Exception: sometimes siding out more engine is justified in certain matchups vs combo decks
  • Going first vs. going second
    • The speaker generally avoids devoting too many side slots to “going first tech”
    • Most decks don’t inherently struggle going first
    • But sometimes you must patch going first if your main deck has cards that are much worse when you start

Step 4: Choose card types (flexibility vs. impact)

Because side slots are limited:

  • Flexibility
    • Prefer cards useful both going first and going second
    • Prefer tools that work across multiple matchups
    • Multi-purpose cards stretch side deck value
  • Impact
    • Very specific counters are usually less efficient unless:
      • The deck is extremely popular, or
      • The matchup is especially difficult
    • Example: Artifact Lancia is used as a specific-but-common answer because fewer flexible alternatives exist

Concrete example: the speaker’s side deck construction (Mitsurugi deck)

The main-deck starting point (why the side deck needs exist)

The main deck already contains targeted tech (examples referenced):

  • Six Small Charms and other specific choices

So the side deck must cover:

  • Matchups not already covered by main-deck cards
  • Situations where main-deck tech is bad (for example, certain cards going first)

Matchup targeting via categories (for their example deck)

Category 1 (must prepare)

  • Malice
  • Mitsurugi Risal (Ryziel / Risal referenced)

Category 2 (prepared but not primary)

  • Variants of Risal
  • Mermail
  • Memento
  • Fimith
  • Blue-Eyes
  • Cres / Crestron
  • Possibly Odon
  • Notes were also made about differences between “pure” Mitsurugi vs the Risal version

Category 3 (not specifically prepped)

  • “Everything else,” handled indirectly by general tools

Example decisions: how many cards to side

Against Mitsurugi Risal

  • The speaker claims they didn’t need to add much because the main deck handles it well
  • Named main-deck cards included:
    • Fuvalos
    • Peruia
    • Droll
    • Dolan Lockbird

Against Malice

  • They wanted more specific hate because main-deck tools (Droll and Peruia) were not as effective
  • Side inclusions included:
    • Lancia
    • Nibiru
    • Additional support (including extra Lances / Nibirus and Mitsurugi trap coverage)
  • They estimate dedicating at least ~5 cards to Malice

Rogue coverage strategy

The speaker identified a “big weakness” they weren’t covering well:

  • B… Smith / Caesar-style decks (with Caesar noted as strong vs Mitsurugi)

Chosen solution type:

  • Bastiles (noted as flexible)
    • Works across multiple matchups
    • Helps against Caesar-makers and related decks
  • Also included:
    • Bald Drake (useful because it can tribute their own Mitsurugi)

Additional niche tech mentioned:

  • Vosu
    • Highly searchable
    • Used to answer Caesar more consistently than some non-searchable alternatives
  • Dimension Shifter
    • A one-of meant to hate on many rogue/combo decks that rely on drawing/continuing their combo

Niche / advanced side-deck concepts mentioned

  • Searchability is a huge value driver

    • Unsearchable side cards rely on drawing them naturally.
    • Searchable side cards (even one-ofs) become significantly more likely to appear in relevant games.

  • Side deck cards that function from the Extra Deck

    • Extra Deck cards effectively don’t need to be drawn when you side them in.
    • Example use case: you can justify not running a tech monster in the Extra Deck main because the mirror is rare.

  • Time rule cards

    • The speaker argues against assuming you must side “time” techs for every deck.
    • Only side time cards if your deck inherently struggles with time (e.g., life point paying requirements, slow gameplay, control archetypes that don’t battle often).

  • “Smoke screening” / engine-swapping deception (rare technique)

    • Idea: hide an entire engine in the side deck and swap it in after sideboarding so the opponent sides incorrectly.
    • Advantage: surprise factor
    • Disadvantages:
      • You must replace a full main package (e.g., all 15 copies of an archetype package) with another engine package
      • You lose flexibility to side in targeted non-engine answers
    • Works only if you can fit two engines (or engine packages) within the available side space and their weaknesses complement each other.

Closing perspective: how side decking evolved

  • Early Yu-Gi-Oh! side deck philosophy

    • Patch weaknesses with moderate improvements
    • Remove suboptimal cards
    • Add matchup tweaks (e.g., backrow removal vs backrow decks)

  • Modern era

    • Side deck becomes more of a “card counter machine”
    • Floodgates and auto-win-ish matchups are more common
    • The speaker notes this is partly driven by why those cards exist, but they personally wish side decks were more used for nuanced optimization rather than hard turning games into non-games.

Speakers / sources featured (as described)

  • Speaker: An unnamed competitive Yu-Gi-Oh! player (first-person narrator) who claims:
    • Long-term competitive experience
    • Multiple YCS wins
  • Referenced example deck/source: “Mitsurugi deck list” from the speaker’s performance at French Nationals (top results referenced in subtitles)
  • Card names referenced throughout subtitles:
    • Nibiru, the Primal Being, Droll & Lock Bird, Artifact Lancia, Ash Blossom, Dimension Shifter, Bastiles, Wosu, Bald Drake, Solemn Judgment, Solemn Strike, Triple Tactics Thrust, Called by the Grave, Triple Tactics Talents, Evenly Matched, Dark Ruler No More, and others.

Original video