I have two ideas for Point Defense weapons.
One of them is a missile screen - it's a Last ditch effort by a ship to destroy incoming seekers. It's just a weapon with a range of one square around the ship. It could have a value of 40-80, so it can destroy one or two missiles depending on the tech level.
My other idea is a seeker. It's like countermeasures fired by a submarine to evade a torpedo. The ship fires the countermeasures and they seek the missile and destroy it.
You could also create a point defense torpedo that "scatters" to inflict damage against a fighter group.
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