So, 3PO's card says when you roll agility dice, you may guess and if correct, you add a result. I know you can guess 0, get a blank, add a result from C3PO, and then lone wolf reroll for a possible second evade.
But can you use C3PO on the LW reroll? The following instance came up earlier where I was shooting chewy at R3 through a rock, so he was rolling 3 agility. As such, the defender didn't activate C3PO, but gambled that he'd get at least one blank, and then he used C3PO on the LW reroll of a single die.
I guess it comes down to - is a reroll the same as a roll?