Game changers are part of the new bracket system being tested by Wizard of the Coast.

These cards dramatically warp commander games, whether having players run away with resources, shift in ways many players dislike, cause people to not be able to play the game, really efficiently search for their strongest cards, or commanders that tend to be only built in ways that take away from more casual games.

• Bracket 1 (exhibition) and 2 (core) decks generally avoid game changers.
• Bracket 3 (upgraded) decks generally run up to 3 game changers.
• Bracket 4 (optimized) and 5 (cEDH) are unrestricted on game changers.

Click here to learn more about Brackets.