The Shield has the ability to protect anything in a barrier that can only be broken by The Sword. It is inpenetrable to all types of magical and physical attacks, even from those of other Clow Cards, minus The Sword. Shield likes to protect things that are most important to a person. It is the defensive counterpart to The Sword. The true form of Shield is a shield that has a "Clow wing" embellished on the front with a red gem encrusted on its side, just as it is depicted on its card face. It is under The Earthy.
The Shield first appears in Episode 11. The Shield had inhabited a locked jewelery box which held something precious to both Tomoyo and her mother. But it made it impossible for Tomoyo or Mrs. Daidouji to retrieve their precious items from the box, going as far as to expell the key to the aforementioned box out of its lock. This would be natural for Shield since it likes Sakura used The Sword card to 'cut' Shield, making it reveal its true self so Sakura could capture it.
After this, The Shield was used two more times, once in the finalé where she used it to block on of Eriol's attacks and then make sure Syaoran and the unconcious Touya and Tomoyo were safe from any crossfire. She then used it again in Cardcaptor Sakura Movie 2: Sakura and the Sealed Card where she used it to block an attack from an ice monster made by The Create while it was under The Nothing's control. It was the last card Sakura had while facing Nothing except for The Nameless Card and was taken by Nothing just like the others.
- It is unknown why The Shield is wrapped in several chains in its card, like The Sword, but it is possible that it is because the card summons an actual weapon instead of an animated spirit.
- i.e. The Arrow summons a young girl to fire a volley of arrows and not just the arrows.