Yeah, the AMS rules are awful when combined with custom ships. If you're limited to canon designs then AMS is reasonable, but if you can add your own AMS freely, then capital missiles are garbage. It's vastly cheaper to knock them down than it is to send them out, and the entire weapon class
effectively dies off as a result.
For a simple change, how about something like this?
- Only AMS systems can be used for point defense.
- Each AMS can only fire once per round, but a hit will kill any missile.
- Unlike most weapons, PD bays do not need to fire together - they're grouped for convenience. The defending player may divide up their PD against any number of missiles as they see fit.
- It takes 10+ to hit a Kraken, 9+ to hit a Killer Whale, 8+ to hit a White Shark, and 7+ to hit a Barracuda or any sub-cap missile, if they are aimed at your ship. If they're just flying by, a +2 penalty applies.
That should allow point defence to be installed in useful quantities without just deleting a weapon class.
If you want to be a bit more ambitious, try these rules:
- Regular PD can only be used against standard-sized missiles.
- A new Capital AMS weapon is added, which weighs 50 tons, has 5 shots per ton of ammo, and generates 10 heat every time it is fired.
- A Capital AMS can fire multiple times per turn. However, if two or more shots per AMS are fired, roll 2d6 - if the roll is less than or equal to the number of shots fired, the weapon jams on that round and cannot be used thereafter. (E.g., if the player attempts to fire six shots, they roll 2d6. If the roll is a 5, then the first 4 rounds fire normally, and the weapon jams on the fifth shot. 60 heat is generated, and the weapon is unavailable for the rest of the scenario)
- As above, bays do not need to be fired together - the player may choose to divide bays between attacking missiles as they see fit.
- Capital AMS automatically hits any missile targeted that passes within Short range(capital-scale) in the appropriate firing arc. One hit kills a Barracuda or any sub-cap missile, two for a Killer Whale, three for a White Shark, or five for a Kraken.
That should provide a more plausible defensive system. You can go all-out to deal with a giant salvo, or play it safe and degrade enemy fire somewhat while keeping your AMS around for future rounds. It may take up a bit too much time/effort for players who don't want to focus on this part of gameplay, but I think it'd be interesting and fun.