Almost, but not quite. Slicer, Mechgun, and Shot are 1/3, while Sword, Partisan, and Dagger are 1/2. Twin Sword is not reduced. Reduction is applied to the final rate, so e.g. Arrest Gungnir on an enemy with 20 ESP is 80 - 20 = 60 / 2 = 30% final rate. If you're an android, it's 110 - 20 = 90 /...