| Shields I vote "all of the above". That is, I don't think that the word "shield" should be rigidly codified. It's used to mean different things in different settings (Star Trek, Fading Suns, etc.), and I think we should allow for different *types* of shield. Each could be described separately in the ship-building components list, with different names (e.g. force-shield, ablative shield) to distinguish among them, and the way each type works would be defined in the description of that component.
A couple of thoughts on the options you described: First of all, if you make a critical hit chart that allows for damage to ship components, it's possible for type I shields to be at 50%; a critical hit to the shields could reduce their AC bonus. Secondly, type II and type III shields could be combined. I'm not sure I like the idea of shields stopping *all* damage (except criticals) until they collapse, but you could have damage-reducing shields that have a maximum capacity to absorb damage. Personal shields in Fading Suns d20 work like this, although they measure damage by number of hits whereas I'd be more inclined to tally up the actual total damage absorbed.
Wyvern
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