In some situations the rules allow you a 're-roll' of the dice. This is exactly as it sounds – pick up the dice you wish to re-roll and roll them again. The second score counts with a re-roll, even if it means a worse result than the first, and no single dice can be re-rolled more than once, regardless of the source of the re-roll.
Re-rolls
Source: Core Rulebook 3E, p. 37
A re-roll means rolling the dice again and using the new result, even if worse, and no single dice may be re-rolled more than once.