Star Wars Imperial Assault Dice Pack: - Rules of Play says:
Keep the focus on the tenseStar Wars battles ofImperial Assault with a tool of convenience: extra dice! TheImperial Assault Dice Pack contains eleven combat dice, identical to the eleven combat dice found in theImperial Assault Core Set. With these extra dice at your disposal, you’ll never need to pause in your games, whether you’re commanding squads of Stormtroopers, or leading an elite team of Rebel operatives.