According to the Wook, there are two types of planetary shields - Encasing and Shutter. Encasing are like those on the Death Star II. It states they "seriously damaged the systems of craft that passed through them", which explains why they needed it deactivated before landing on Endor.

​How would you represent this is game mechanics? It needs to be serious enough I think to stop crews just floating through shields when they feel like it then repairing the system strain.

I'm considering a system overload (reducing strain to zero) with an additional component critical hit to represent something being blown out by the overload.

Too harsh? What do you think? There has to be a reason why fleets don't risk it when they're trying to capture a shielded enemy planet.

Treat it as an automatic Heavy Ion cannon hit, maybe?

You could just set a default damage number for passing through it, be it Strain or Hull or both. Another option might be it inflicts X number of crits automatically. If you want it to have a real impact.

I don't know. I would treat it like lava. Your ship touches it, it dies. That's how they acted in Return of the Jedi.

Treat it like falling damage, but on planetary scale.

Treat it like falling damage, but on planetary scale.

This isn't a bad idea. Instead of basing the damage on range bands, base it on speed.

Inflict plot damage. If you hit the shield you are removed from combat.

Yeah, something like Collision damage might be appropriate. Several automatic Component Criticals = fun times.