How do tarot trump cards work in tarot games?

In tarot games, the 21 illustrated cards known as trionfi (or trumps) function as a fifth suit that is superior in power to the four conventional suits. These cards are typically numbered I through XXI in increasing rank.12

When playing, the following rules generally apply:

• Trick-taking: Players must follow suit to the card led if possible. If a player cannot follow suit, they are obligated to play a trump card.1
• Superiority: Because they are trumps, these cards "triumph" over cards from the other four suits, allowing them to win tricks regardless of the value of the non-trump cards played.12
• The Fool: The unnumbered "fool" card acts as an exception. In most games, it can be played at any time to avoid following suit, serving to protect high-scoring cards. In some central European variations, it functions as the highest-ranking trump.1

The primary objective in most tarot games is to win tricks containing high-value cards, with the trumps themselves often carrying significant point values.1