what is side deck in yugioh Complete Custom for Yu-Gi-Oh! Side Deck Theory: The Basics

Games are meant to be fun

When a "Crystal Beast" monster you control is destroyed by battle and sent to the Graveyard: Place 1 "Crystal Beast" monster from your Deck face-up in your Spell & Trap Card Zone as a Continuous Spell Card, then you take no Battle Damage for the rest of this turn

The player flips the card over and orients it vertically

the Levels of both that monster and this card become the combined original Levels of those 2 monsters, until the end of this turn

The protagonist, Yusei, is a master at turbo duels, a new form of dueling with motorcycles and special speed spells

If a TO plans on pre-registering Duelists for the Regional Qualifier, the TO may only pre-register a maximum of 75% of the expected attendance