When you play a unit with a 'when you play me' effect, if your opponent reacts and kills or returns the unit to hand, does the on-play effect still trigger?

Ruling: The trigger will always resolve and go on the chain, but it may have no impact on the board depending on the wording of the ability.

Sequence:

• The unit is played and enters the battlefield
• The "when I'm played" trigger goes on the chain
• Opponents can react to the trigger (but not to the unit itself being played)
• The trigger resolves based on its wording

Nuances:

• If the ability references "here" or "me" and the unit has been removed, the game returns a null value and the ability resolves without effect
• If the ability does not reference a specific location or the unit itself (e.g., "all enemy units get -3 Might"), it will resolve normally even if the unit is no longer in play
• Units cannot be countered while on the chain - only spells can be countered by effects like Defy
• Units are permanents and resolve too quickly to be targeted while on the chain under normal circumstances