Planetary Ion Cannon

A ship may use Thermal Shields to remove dice while defending against an attack from Planetary Ion Cannon.

Reference

This objective is not recommended for Task Force play.

This card’s Special Rule effect can only be used to attack 1 enemy ship per round.

While attacking with this card’s Special Rule effect, if the defending hull zone has no shields, the attacker can choose to resolve the standard critical effect instead of the card’s critical effect

The standard obstacles are used during setup, which are 3 asteroid fields, 2 debris fields, and 1 station. After obstacles are placed and before deployment, the second player places 3 objectives tokens in the play area beyond distance 5 of both players edge.

The special rule:
At the end of the Command phase which is after command dials are set for both players but before the ship phase and any player able to resolve any card effects in that timing like for example Reinforced Blast Doors, if a first player ship is at distance 1-3 of an objective token, the second player may choose to remove that objective token from the play area and perform an attack against that ship. Only 1 objective token attack can be resolved per round. This attack is treated as if a ship were attacking with a battery armament of 4 blue die. This attack is not considered friendly to your fleet and cannot resolve any effects your fleet could otherwise provide.
The attack is at medium range, cannot be obstructed by an obstacle or card effect, and can target any of the defenders hull zones. This attack is also granted a critical effect, if the attack pool contains a blue critical icon in the “Resolve Damage” step, the defender must choose and exhaust 1 of his defense tokens. The defender needs to choose a readied(green) defense token to exhaust, as you cannot exhaust a defense token that is already exhausted.
If the defending hull zone has no shields, the attacker may resolve the standard critical effect instead in the “Resolve Damage” step.

A defending ship that spends a contain defense token and also has Damage Control Officer equipped (and not discarded) will prevent any critical effects from resolving.

A defending ship that has Commander Gherant equipped (and not discarded), the attacker cannot resolve any critical effects.