Xyz Monsters are types of monster with a black frame. Xyz Monsters don't have a Level. Instead they have a Rank, which is displayed on the opposite side of the card to where the Level Stars would be. The Rank of an Xyz Monster gives a clue as to how to Summon it. Rank 2 Xyz Monsters are Summoned using Level 2 monsters, Rank 3 Xyz Monsters are Summoned using Level 3 monsters, and so on. The Xyz Monster itself will tell you how many monsters you need to use in the same place that a Synchro Monster tells you what monsters you need to use. Unlike Synchros, you can usually make Xyz Monsters out of any 2 monsters that are the same Level.
How to XYZ summon
Just like Synchro Monsters, Xyz Monsters have their own type of Summon that you perform when you want to play them. Here’s how Xyz Summons work: When you control 2 face-up monsters with the same Level, they would be put on top of each other, then the appropriate Xyz Monsters would be put on top of them. Note that the materials are listed on the card like any other extra deck mechanic and will sometimes require more monsters to make
Like for example Loading... requires 2 level 4 monsters to make. The monsters you used to Summon it become the “Xyz Materials” of your Xyz Monster and are not sent to the Graveyard; instead they stay under the Xyz monster until you use them for that monster’s effects or the Xyz Monster is destroyed. An Xyz Summon is a type of Special Summon, just like a Synchro Summon, and it follows all the same rules for reviving your monsters if they are destroyed.
The monsters you use for an Xyz Summon don’t go to the Graveyard, they stay under the Xyz Monster until they’re detached from it. The effects of Xyz Monsters usually tell you to “detach” Xyz Materials from it. When you use those effects, you “detach” the Xyz Material by sending one of the cards beneath your Xyz Monster to the Graveyard.
New mechanic means new rules to follow or know about for all the newbies out there:
So firstly Xyz Materials underneath Xyz Monsters do not count as monsters, so detached Xyz Materials will be sent to the Graveyard regardless if there’s a card that would let them be banished or return from the hand. While monsters are acting as Xyz Materials, they cannot be targeted nor apply their effects. Also even if the Xyz Monster would be flipped face-down by cards like Loading... or Loading... or gets stolen by the opponent by using Loading... , the Xyz Materials will stay until the Xyz Monster moves from the field to a zone other than the field like using Loading... to destroy it or Loading... to banish the XYZ Monster.
Leaving the Field
Some monsters have effects that activate when they “leave the field”. For example, these effects activate when the monster is sent to the Graveyard, or is banished, or is returned to the hand or Extra Deck. When a monster on the field is shuffled into the Main Deck, or becomes an Xyz Material, it is no longer a card on the field. However its effects that activate when it “leaves the field” will not activate. A good example for one of those cards is Loading... . Also do note that Tokens cannot be used as Xyz Materials, because Xyz Materials are attached to the Xyz Monsters and attached Xyz Materials are not considered to be on the field.