For Yu gi oh what does that little shiny square in the right hand corner mean?

You're likely referring to the "Rare" symbol found in the bottom right corner of some Yu-Gi-Oh! cards.

Here's a breakdown of what the different colored squares mean:

* Silver square: Common (most common rarity)

* Gold square: Rare

* Blue square: Super Rare

* Purple square: Ultra Rare

* Red square: Secret Rare (usually holographic)

* Black square: Ultimate Rare (the rarest of the rare)

The rarity of a card influences its value and playability. Rare cards are generally more powerful and sought after by collectors.

Keep in mind that some older cards may have different symbols or no symbols at all, depending on their set.