Side Deck

A 'Side Deck is a collection of between 1 and 15 cards, separate from the Main Deck. The Side Deck is used in Matches between Duels, to alter the contents of the Main or Extra Deck. Previously, the Side Deck could not be used to alter the contents of the Extra Deck, though this has been changed. This is done to better suit a strategy against an opponent's Deck.

For example, a Burn Deck, a Deck based around dealing direct damage through Card Effects and Spell Cards, could be easily countered by including several cards to prevent Life Point damage, such as "Des Wombat".

Common Side Deck cards include various forms of Spell and Trap removal (such as Dust Tornado) and cards that can directly counter common strategies (such as Prohibition and Imperial Iron Wall).

However, a Side Deck is not compulsory, in which case, a value of 0 for a Side Deck is also considered legal. In both the OCG and the TCG, any value between 0 and 15 inclusive is permissible.

Rules for KDE Sanctioned Tournaments have not changed, however. For KDE Tournaments, you still must have either 0 to 15 cards exactly in your Side Deck.