Learn Italian: La tua pedina va indietro di una casella. - Your token goes backward by one square.

In Italian, you almost always need a definite article (like il or la) before a possessive word, so it literally translates to "The your token". The main exception is with singular family members, where you drop the article (like tua madre). Since a pedina isn't a family member, it requires the La.

What exactly are a pedina and a casella?

These words are common board game vocabulary! A pedina is a playing piece, pawn, or token. A casella is a square or space on a game board, like you would see in Chess or Monopoly.

Why is the preposition di used to mean "by" in di una casella?

When you want to express the exact measure or amount by which something changes in Italian, you use di. Here, the backward movement is measured by one square, so it becomes di una casella. You will also see this rule in comparisons, such as being taller "by two centimeters" (di due centimetri).

The token goes backward (indietro). How would I say it goes "forward"?

The opposite of indietro is avanti. So, if you are winning the game and your token goes forward by one square, you would say La tua pedina va avanti di una casella.