Is Rock-Paper-Scissors played by pumping my arm 2 times then throwing my choice, or pumping 3 times then throw?
According to the current "Play! Pokemon TCG Tournament Rules and Formats" document, the procedure is a three-count priming and then the simultaneous throw of the choice, for example, "Rock-Paper-Scissors-Shoot" with the choice thrown on "shoot".
Source: PUI Rules Team (2008-10-16), TPCi Rules Team (2013-11-21)

Relevant cards

Note: All applicable cards may not be listed below.
BW11_56