I have a Gozanti with Ordnance Experts to support a couple of TIE Bombers flying as escorts. The bombers are equipped with Cluster Missiles.

When a bomber fires Cluster Missiles, does the Ordnance Experts effect happen on both Cluster Missile attacks or only one?

Thanks.

You would be able to use Ordnance Experts twice, because it's an effect that triggers during "Attacker Modifies Attack Dice", which happens twice during a "Perform This Attack Twice" attack, except for the part where Ordnance Experts says "Once per round...."

Only one, because Ordnance Experts says "Once per round."

If it didn't say "once per round", then you could use it once on each of the two cluster attacks.

Remember, Cluster Missiles still makes two separate attacks. Anything that can be done "when attacking" can be done once on each attack, but you still have to pay the cost each time.

If your Ordnance Experts are supporting two bombers, that's four attacks available to trigger the Ordnance Experts, but the "once per round..." means only one of those four attacks will benefit from it.