Can you react when a gear or unit is played if it has no immediate ability activation?

Ruling: You cannot react when a gear or unit is played unless it has a trigger effect (like an ETB). Both units and gears without immediate abilities go on the stack but resolve straight away before allowing a reaction.

Sequence:

• When casting Units/Gears without abilities that happen immediately, a chain gets created
• The chain immediately resolves, leaving no window for reactions
• The permanent leaves the Chain and becomes a Game Object

Nuances:

• You CAN react if the gear or unit has an ETB (enters-the-battlefield) or other trigger effect