Knowing your deck is vital to understanding and playing Yugioh! You have to know what your cards do and how they interact. And not only do you have both a Main Deck and an Extra Deck to maintain, there is also the Side Deck! But, what is a Side Deck, how is it used, and why is it important? Let’s take a look together!
The Side Deck

What is the side deck? In Yugioh!, the Side Deck is almost like an extra Extra Deck that can also hold Main Deck cards. The Side Deck is a collection of cards that you build that you can access in between games in a match. A Yugioh! match consists of three games, and in between each game, both players have the opportunity to access their Side Deck and swap out cards from their Main and Extra Decks with the Side Deck. This can be very useful when playing a match as it allows you the opportunity to try to counter your opponent’s strategy or cards after learning what deck they are playing.
Using the Side Deck
As mentioned above, you can only access the Side Deck in between games during a match. When a game ends, both players can use their Side Decks to swap out cards from their Main or Extra Deck with their Side Deck. For example: say you have Ghost Belle Haunted Mansion in you Mian Deck, but you discover that your opponent is playing very little Graveyard interaction. During Side Decking, you can swap out Ghost Belle for something more potentially useful like Droll and Lock Bird or Effect Veiler.
Importance
What is the importance of the Side Deck? Well, it is important because it can help you win a match by letting you exchange cards in your deck for more useful ones. Once you see what cards and strategy your opponent is using, you can tap into your Side Deck for counters to their game. It is a way for you adjust your deck during a match to give you an advantage over your opponent.
Tips

The way the Side Deck has been used throughout Yugioh!’s history has changed. It used to house generic staples like Mystical Space Typhoon, or floodgates like Anti-Spell Fragrance. It has also been used for counter strategies, such as simple (literal) counters like Solemn Judgement to specific archetype counters like Artifact Lancea against Maliss or Invader of Darkness against Radiant typhoon. This is more like a meta-counter strategy – loading your Extra Deck with specific counters to specific archetypes, decks, or strategies. It can be wise to use hand traps in your Side Deck so you can swap them out depending on your opponent’s deck. It is also advised to use non-engine, generic support cards in the Side Deck that can be teched into any deck, like Triple Tactics Thrust, Harpie’s Feather Duster, or Skill Drain. Extra Deck monsters are not ideal options for the Side Deck, as they take up too much precious space for other cards.
Try building an Extra Deck today and see how it can help improve your gameplay!