More discussion on this later*, but in general terms:
The simple method is for weapons to degrade uniformly. At each damage step (1/3 and 2/3 of the total), a die roll is made:
ROLL : RESULT
1 : None
2-4 : Apply a -1 firing penalty to all attacks
5-6 : Apply a -2 firing penalty to all attacks
The reasons for these penalties are not really important (i.e. are individual weapons lost? Is the rate of fire being reduced? Is energy bleeding out?); the effect is that the firepower of a ship's weapons is being reduced.
The more advanced method is to track damage to individual banks. At each damage step (1/3 and 2/3 of the total), roll one die per bank:
ROLL : RESULT
1 : Bank is destroyed
2-3 : Bank is damaged; apply a -2 penalty
4-6 : None
A second "damaged" result indicates the bank is destroyed.
The nice thing is, since the overall effect is identical (an average loss of 1/3 firepower at each damage step), each player can decide how to track damage for himself, and the game will still balance out.
*I'm planning on a few more "Designer's Notes" mini-articles, including one on movement, one on defenses, and one on how ships are damaged/destroyed.
Daniel Kast
Majestic Twelve Games
cricket@mj12games.com