What are the consequences of making an error in a reply brief?

Arguments first made in a reply brief are forfeited. (People v. Tully (2012) 54 Cal.4th 952, 1075.) Even if we were to consider the argument, we would reject it, since the three separate forms the jury was given for the rape convictions did in effect require it to make separate findings about each. Finally, any error was harmless under any standard, because, as we have said, in light of the evidence presented, there was no rational way for the jury to find some but not all of the rape priors true.