A new system!
Most weapon systems may be linked together. This allows the weapon systems to "pool together" the damage they inflict towards Critical Hits. All weapon system linked to each other must be fired at the same target. Roll to hit for each weapons system separately. Roll the damage for each successful hit as normal but use the total damage for all the linked weapons fired to determine if a Critical Hit has been made.
Example: Three linked small missile launchers fire at a target. Each gets its own to-hit roll; one misses, the other two hit. A 6 and a 4 are rolled for the damage, but the two are added together for the purpose of determining a Critical Hit. As 6 + 5 = 11, a Critical Hit has occurred.
1) Melee weapons may not be linked.
2) Up to six weapon systems may be linked together but they must all be identical, even down to the ammo type (HE, AI, or AP).
3) All weapon systems that are linked together must have the same arc (Front, Back, Left, or Right).
4) Linked weapons may not be "unlinked" during a battle, nor may "unlinked" weapons be linked during a battle, but may be changed between battles.
5) Weapons systems in different mechs cannot be linked together.
6) Loss of linked weapon systems due to Critical Hits do not destroy the links. If you had 3 small missile launchers linked together and one was destroyed, the remaining 2 would still be linked together.
In short, linked weapon systems will improve the chance of a Critical Hit against a target, but lose some tactical flexibility and burn through ammo a bit faster.
Cost: zero spaces. Yep, it's a freebie.