Stone Idol Trap

If you cast Stone Idol Trap during your opponent’s declare attackers step, the Construct token you put onto the battlefield will be able to block that turn.

The cost-reduction ability doesn’t care who controls the attacking creatures. If you like, you may cast Stone Idol Trap during your own combat phase, in which case it will count your attacking creatures. If you do, however, the token you put onto the battlefield will be unable to attack that combat and will be exiled later that turn.

This Trap doesn’t work the same way as other Traps. Rather than having an optional alternative cost, Stone Idol Trap has a mandatory cost-reduction ability.