Concise description:
every ten (or eleven, I'm still open to suggestions) rolls, you get an extra dice to roll upon your discretion.
Specifics/Details:
basically you can accumulate extra dices rolls, to be used on a special occasion.
you can spend these extra rolls when attacking having the possibility to throw 4 dices instead of three (or two instead of 1 or three instead of 2)
you get a check box and when you thick it, you throw an extra dice for each attack until you use all the bonus - or until you uncheck the box.
How this will benefit the site and/or other comments:
you would get an option to "motivate" and increase troops' performances.
I believe it might compensate or reduce the effect of luck.
in general it might deepen the gameplay
you will have the option to choose important battles