Prison Planet

[The Tatterdemalion King]

No prison is so impenetrable that PCs can't destroy it. Realistically, such a super-max prison would have the same shields as a starbase. Anything less is not taking it seriously, and anything more is ludicrous.

To get technobabbly for a second, shield strength presumably derives from two things: the amount of power the generators make, and the ability to project that power into the shield itself (which consists of both emitters and power-conveyance systems). In a starbase, the amount of generators hooked up to shields is probably restricted by the size of generators in relation to the amount of space the shields have to cover while still providing synced-up coverage, but on a planet you can have really big generators projecting a shield that only has to cover a portion of the area.

But—and here's the big thing—we don't really have any serious discussion of planetary shields in Trek. We don't know what just activating a giant shield within a planetary atmosphere even does. I imagine it's not the best for, I don't know, birds or normal weather patterns. And then you get complicated things like whether or not the shields have to extend into the crust to avoid phasers side-drilling at the target through the planet, or whether they have multiple layers of shields projected into the ionosphere or whatever. (Giant hovering shield-projector platforms are coming to mind.) So an asteroid might have the ability to use shields in a way that a city on a planet might not.

[Omega1967]

I was thinking of something that is a little more than a knock on the door and less than kicking it in.

[The Tatterdemalion King]

The thing is that local transport inhibitors seem to be the kind of things that can't be gotten around be starships, which means that shields or not a prison break is going to need a laterally-inserted extraction team.

[Owen E Oulton]

You don't need to surround the whole planet. Rura Pente showed that, An airless planetoid would be better than an arctic wasteland, though...