Affects Others is an enhancement found on page 107 of GURPS Powers
Maneuver[]
P154 reiterates that a Ready maneuver must be used.
Special rule[]
This has a unique interaction with Shapeshifting. It is the only modifier which, in addition to affecting the base cost (15/form or 100) also affects the 90% difference.
Advantages[]
Pyramid 1 (Kromm's article) and 75 (A Familiar Path) discuss it's interaction with Energy Reserve.