When can I use a courtesy runner?

Under Rule 8, Section 10, you may use a courtesy runner for your pitcher and/or catcher once she bats and reaches base safely. She doesn't leave the game.

• The same courtesy runner can't run for both the pitcher and the catcher in the same game.
• In the top of the first inning, the pitcher and catcher are the players listed at those positions. After that, they're the last players who actually played those positions on defense, so report defensive changes at pitcher and catcher to the umpire.
• Normally, a player who is in the game or has already played can't be a courtesy runner. In JO fastpitch pool play, any eligible player can be.
• If the courtesy runner's own turn at bat comes while she's on base, the player she's running for is called out and the courtesy runner goes to bat.
• A courtesy runner who isn't reported, or isn't eligible, is an illegal runner.