One of the most interesting things about the GalCiv2 combat model, to me, is how things change with tech level. In a lot of games, it's common to have things in a sort of stasis. In the beginning you have ships with 10hp, 10 attack, 10 defence and later you have ships with 100hp, 100 attack, 100 defence. In GC2, we have two mechanisms that really go against the usual lock-step scaling.
1. Base ship hitpoints hardly increase at all compared to potential attack and defence values. The only major source of new hitpoints is experience and larger hulls (tech increases to hitpoints are fairly minor). The larger hulls are mostly a wash, since they also include more firepower. Experience can't apply to everyone since any time two opposing, experienced ships meet, one is going to die.
2. Non-optimal defences become less and less useful. At the start, an X/1-1-1 ship is equivalent to 3 defence in everything (it might actually be better, if the 3 defences are 3 separate rolls). At technology marches on, the only really significant contributor to defence is the optimal type.
My question: what do these changes mean for the viability of defence? Clearly, as technology progresses, it takes a larger and larger commitment to defence to give your ships a reasonable chance of surviving if they are ambushed by an all-attack force.
One way to respond to this is to get out of the defence game entirely, and commit to always being the attacker, not the 'attackee'. Certainly this is viable against the AI right now, as it undervalues both movement and first strike. If you face an opponent who is as skilled as you, however, there are some drawbacks. First, to always be the attacker, it's hard to hold ground. As opponent speed increases, the buffer of space you need to give them goes up too. If the opponent has multiple staggered fleets, it becomes increasingly hard to engage one without being in range of a counter-attack from another. You also run into problems as speed starts to bump up against the maximum sensor range.
Another factor: if your opponent is using the same 'eggshells with sledgehammers' approach, more and more of your attack is going into overkill, especially facing small/tiny ships. If you are facing tiny ships with no defences, going from 15 to 20 attack has reduced marginal gain. Clearly, commiting to *some* defence is probably going to be useful even late game, since it allows you to use starbase defence boosters, and the marginal cost in terms of lost expected damage per round is fairly small.
What about a big commitment to defence? I don't see how this would make sense on the smaller ships, since it would be hard to put on enough defence and still have enough firepower to kill the enemy quickly. Defence is more efficient in larger ships that are fighting smaller ships (you get to fire your defences more times, on average). One rule of thumb is that a defence equal to your opponents attack reduces his expected damage (and therefore increases your life expectancy) by a factor between 2 and 3 (approaching 3 in the end game). In the long run, in a 'high hitpoint' world, this is equivalent to multiplying your attack score by 2 or 3 against an undefended opponent. In a 'low hitpoint' world, this is both better than the 2 or 3 multiplier (less damage lost to overkill) and worse (you might not survive the first round, regardless).
Anyway, I don't have a good analysis on this stuff, and clearly it depends on what the other guy is doing. What do you guys think?
