So I traded for a spanish metalmorph the other day...
It has the official Konami symbol on the back (same as english cards) The card's title is in english, and so is that symbol. The text is simply in Spanish. Do you think I can use this card outside of casual duels? Thanks

THE GOD DRAGON

Yes you can use it.
Yu-Gi-Oh! Policy
A-5 Legal Cards: Overview

Yu-Gi-Oh! cards become tournament-legal around the world at the same time. When a set becomes legal in North America, it also becomes legal in Latin America, Europe, Australia and other areas outside of Asia.

When using a card that is not in a local language, a local language version of the card or an accurate card translation must be available outside of the deck to show to any opponent. This will help ensure that both players understand exactly what the card does.

Japanese, Chinese, and Korean cards are not legal for tournaments. "Asian-English" cards are not legal for tournaments. The English "God" cards are not official
Yu-Gi-Oh! TCG cards and are not legal for use in decks. They have no effect on games and cannot be summoned to the field.

i play foreign cards in my deck also.

i have a Spanish version of Swords of Revealing Light, and French versions of Exodia's Head and Right Arm.

i'm working on more... just kills me when the opponent sees them and doesn't immediately recogized the card due to the foreign names.