Protect them from mechanical damage
While the game would only limit or semi-limit cards during these days, other cards forced Yu-Gi-Oh
What else to say
These cards can be identified by their rainbow card names and distinctive holofoil effect on the card art.
Buyers use shorthand like NM (near mint), LP (lightly played), MP (moderately played), and HP (heavily played), and eBay has its own condition menu for trading cards, too, and you should know that a little edge whitening or one soft corner drops a card a grade, and pretending otherwise is how you collect returns
While the biggest addition in the set are Pokmon Tool cards, which can be attached to specific Pokmon to add certain effects or benefits, most players will be looking at the new Pokmon ex cards, which usually form the backbone of new decks