**Essential**

* have interesting things to do while confined
* have choices of what to do while confined.
* telescope time in confinement as long as players want.
* remember that no GM's list of the ways out should ever be exhaustive 
* remember that confinement is a normal tool of dungeon crawls. 

**Useful**

* have a reason they want to get out (or to stay in)
* have some clues for a good way to get out
* have multiple ways out allowed for
* have a good reason they have been confined

#Interesting things to do

Any place with interesting things for characters to do is a good place for adventure. This can include people to interact with, things to make, and information to share.

#Choices to make
All the interesting feels railroaded if there's only one path. Therefore, let the players make choices. 

Likewise, if the choices all lead the same place, players tend to catch on... and then get upset. So, make certain the choices are meaningful. 

This means also not letting the players notice the rails.

#Telescoping Time

If they want to hide in their cells for a week, fine, let them. Narrate the routine they notice.

Likewise, if work is a major part of that prison's environment, no need to dwell on the work. Roll for interesting discussion partners, but generally, reduce work to, "you spend the next 8 hours hacking at the mine walls with picks."

#The list isn't exhaustive
As a GM, you are not going to have a complete lis of every way in or out, nor every possible circumvention of the defenses.

So, if they come up with something new, run with it. If it makes sense, let it work.

#Confinement is Normal

Classic D&D Dungeons are a clear case of a railroad with choices that matter... each hall is a chunk of rail, and each room and junction a meaningful choice.

#Give them a reason to get out (or stay in)

If you want them to engage with the prison itself, give them either a strong reason to leave, or a strong reason to stay and play within.

But, by the same token, if they want to just do the time and get out, don't take it personally... resolve a few "encounters" per month, and let it go by.

#Give them clues & Multiple ways out.

If you want them to engage in an attempt to escape, you need to provide the clues for at least two different methods out. Let the players work on a plan. Let them slowly build a reasonable map. Give them the tools to make it out alive, but also let them know what the hazards are. 

And whatever you do, if they try the brute force method, remember that it's Okay to kill PC's who do stupid.

Further, remember: a well clued set of 2+ ways to escape means at least one meaningful choice: which way to go. Make certain that the various ways have different risk levels.

#Have a reason they're in there
Confinement as a deus ex machina event is bad. Confinement that makes story sense is not bad, but might not be good, either.

Confinement for reasons the players can see coming really does make the confinement itself more enjoyable.

Even if the reason they're there is wrong, it needs to be plausible. So, if locked up for a murder they didn't commit, it needs to have been plausible that they could have... 

... unless it's an obvious frame-job. But then the frame is the reason they're in, and it needs to have a reason.