Implement Bonus

Beginning at 1st level, while wielding a rod, staff, or wand, you gain an implement bonus to all of your to-hit rolls with all Melee Touch Attacks and Ranged Touch Attacks. This bonus does not apply to any normal (non-touch) attacks you make. This bonus can only be applied to spells or spell-like abilities that you cast, and that require a touch attack.

The implement bonus is equal to +1 at 1st level, and increases by an additional +1 per 4 class levels, dropping fractions, to a maximum of +9 at level 33 (i.e. +2 at 5th, +3 at 9th, +4 at 13th, +5 at 17th, +6 at 21st, +7 at 25th, +8 at 29th, and +9 at 33rd). Note that, if you multi-class into another class that also gets this bonus, the class levels stack for purposes of calculating this bonus.

If you are not actively wielding a rod, staff, or wand, you do not get this bonus.

Furthermore, casters can flick, twirl, or swoosh a wielded rod, staff, or wand to complete the somatic gestures of any spells they cast, in place of using their empty hand(s). That is, these implements count as an empty hand for purposes of completing somatic gestures.