If you play a unit from hidden that gains might from passive effects (like Trifarian War Camp and/or Shield from being a defender), does Volibear's 'when you play a Mighty unit' ability trigger?

Ruling: Volibear will NOT trigger when playing Teemo Scout with Trifarian War Camp, because Teemo's "when you play" ability is a triggered ability that goes on the chain, and Volibear checks when the unit is played (before the triggered ability resolves). For the Pakaa Cub scenario with Shield and Trifarian War Camp, the rules are not clear enough to definitively answer whether Volibear would trigger.

Sequence:

• When a unit is played, it becomes a game object and gains passive abilities
• "When you play" triggered abilities go on the chain
• Volibear checks the unit's might when it is played
• For triggered abilities that modify might (like Teemo's +3), these resolve after Volibear's window has passed

Nuances:

• Shield is a passive ability ("while I'm a defender"), not a triggered ability
• Defender status is assigned during cleanup after a unit is played
• The rules don't clearly specify whether passives affecting a unit apply before or during the "when you play" trigger window
• Cleanup steps happen in order but nothing can interrupt between steps, so they functionally happen simultaneously
• The community consensus is that the rules need official clarification for the Shield + defender scenario