Mindshield's primary use as a Kai Discipline is to protect against psychic attacks in combat, mainly Mindblast. It also protects against mind readings and attempts to influence your mind. Some opponents with more powerful Mindblasts cause EP losses each round you fight them, making this a very valuable discipline to preserve EPs.
The Magnakai and Grand Master versions of this discipline are Psi-screen and Kai-screen.
Mindshield is referenced a total of 25 times in the books, of which 9 times are inside combat.
| Book | Times | Inside combat |
| Flight from the Dark | 5 | 1 |
| Fire on the Water | 3 | 1 |
| The Caverns of Kalte | 5 | 2 |
| The Chasm of Doom | 2 | 0 |
| Shadow on the Sand | 10 | 5 |