Play Effects are Triggered Abilities whose Condition includes the Permanent that has the Play Effect being played to the board. 1. These are commonly structured as “When you play me…” for Units and “When you play this…” for Gear. 2. These Triggered Abilities are put on the Chain as Pending Items after the Permanent these effects correspond to is finalized and enters the board. 3. These Triggered Abilities can be referred to as Play Effects. 4. Abilities that trigger when another object is played are not considered Play Effects.
§ 383.4.a Core Rules PDF (officieel)
§ 383 Triggered Abilities are repeatable effects that happen when a Condition is met.
§ 383.4 Some Conditions are commonly used and structured in a way that explicitly defines their use and other properties of the Effect that is associated with it.