I think it is all dependent on both the tech levels involved and the assumptions made about fighters in any given setting.Gareth_Perkins wrote:Will that not create a situation where bigger is almost always better (in all situations unless background materiel strongly emphasizes the lighter craft)?
A lot of my baselines for fighters in VBAM come from the old Babylon 5 conversions. Fighters are an important element in Babylon 5 combat, and usually have some pretty hefty firepower relative to other settings. In the Babylon 5 Wars game especially, the "heavier" the fighter the larger and more powerful it was.
Here are a few of the B5W fighters that I have converted over into VBAM stats:
Aurora Starfury
Heavy Fighter, Cost 1/2, Maint 1/10, DV 3, AS 3, AF 3
Thunderbolt Starfury
Heavy Fighter, Cost 1/2, Maint 1/6, DV 4, AS 3, AF 3, Atmospheric
Nial Heavy Fighter
Heavy Fighter, Cost 1/2, Maint 1/6, DV 5, AS 4, AF 4, Stealth, Atmospheric
Sentri Medium Fighter
Medium Fighter, Cost 1/3, Maint 1/12, DV 3, AS 2, AF 4, Atmospheric
Frazi Heavy Fighter
Heavy Fighter, Cost 1/2, Maint 1/8, DV 3, AS 3, AF 2, Atmospheric
Delta-V Light Fighter
Light Fighter, Cost 1/4, Maint 1/16, DV 2, AS 1, AF 2*, Atmospheric
In this setting, heavy fighters are more capable than their lighter counterparts. Why then would anyone build the lighter fighters? The biggest reason is maintenance costs. It is nice to have the largest, best fighters you can have aboard your carriers -- but it can get expensive really fast. In most of my games, the light fighters tended to be used as attrition forces that were cheap to build, cheaper to maintain and could serve in a specific role in the fleet.
A universe with a more "traditional" view of fighter craft is the Wing Commander universe. Taking a look at the first game in the series, you end up with the following fighters: Hornet, light interceptor fighter; Scimitar, older multipurpose medium fighter (with extra emphasis on AS); Raptor, heavy bomber fighter; and Rapier, a new multipurpose medium fighter. In that setting, there is a good reason to field some or all of the fighters.
When it comes to designing fighters via a design system, however, usually you end up making tradeoffs on the stats. You may start with one of the archetypes (light, medium, heavy), but how you use the volume/mass determines the unit's qualities. You can improve the fighter's DV (representing better armor/shields, faster speed, smaller targeting signature, etc.), or you can invest them into the ship's combat stats or other abilities. I tend to play pretty low-tech VBAM campaigns, so it is not uncommon to see fighters (even heavy fighters) whose stats are simply craptastic. A medium fighter with DV 1, AS 0, AF 0? Yep, best that they could field!
I do admit that costing for flight units that exist in a set universe could be tweaked to better encourage players to purchase lesser models, but I have never personally encountered this as being a problem in my own campaigns, probably because the smaller/cheaper units still had some sort of unique benefit that made them attractive.