Sack Attack R6 refers to VEXrobotics for the Official VEX Products. What is the official listing; I still have 3-wire motors but did not see them listed for sale?
3-Wire Motors have been discountinued, thus they fall under <R5d> of the VEX Sack Attack Game Manual.
Thus, the 3-Wire Motors are legal.
I was hoping for a explicit list of legal items. Last year we had an issue at a regional and it took a discussion between several judges to make a ruling.
The explicit list is the collection of all products available at www.vexrobotics.com, minus the exceptions mentioned in the VEX Sack Attack Game Manual. If there is any issue over the legality of part, please remember <R5a> which is quoted below for your convenience. Some text has been bolded for emphasis.