Capture scenario?

Have you ever run a capture scenario? If so, in what system? How did it go? How did you adjudicate the rescue/escape?

(I'm thinking especially of scenarios where the fact of being captured is the fosuc/challenge of play. The Slave Lords isn't a capture scenario, as the capture and release is just colour to set up a survival scenario.)

I've done two one with 3rd ed DnD and one with 4th ed DnD. Both went pretty well.
The 3rd ed one the party woke up in a prison, and we did a prison break. Which went really well.
The 4th ed one was a little harder. Mainly avoiding player panic that they have been captured. And they should wait for an opportunity to escape.
Adjudicating is as any part of the game skill checks for finding/gaining too open manacles, watching guard patterns etc. And then combat to overwhelm guards and get out etc.

There's one subset of capture scenarios I would handle differently. I dislike intentional capture scenarios where the only way forward with the plot is for the players to lose. If there's no chance of affecting the outcome, don't roll dice. It will show you if you really have player trust or not.

Though if you want to deal with it like that, get your players in on it and have them give a montage of how they were captured, including the clever ways they were taken down and the heroic but just-short methods they tried to escape / take down their foes.

I've been part of captures as a player several times, usually done with overwhelming force to set up the next act of the adventure. Which makes it feel like they can bring forth enough power to overwhelm you when attempting a capture but not enough on their home turf to keep you. Eh? It was better when the PCs submitted to capture, such as surrounded by guard to go on trial and they don't want to kill the guards.

I've been part of "hey maybe capture" scenarios, where it's not determined ahead of time. Good play and luck can stop all/some of the party from being captured. You do need to be aware that forcing a potential party split like that means some players will sit around bored - that's the same penalty for killing them off so don't make it too long.

Be prepared for some character escaping (invis, teleport, disguise, etc.) even if you intend a full capture, and how you will make it interesting for everyone without much player down time as you swap back and forth. Including rescue attempts.

I've a few times had partial-capture scenarios, where one or more PCs got caught while the rest escaped. It ends up as pretty much a simple split-party scenario particularly if the captured group somehow escapes, with the hard part being keeping the timing together (such that with two or more groups of moving PCs you always know who is where when, in order to determine who meets or doesn't meet each other) but the players apart (to avoid knowledge spillover and metagame concerns).

I've had two of these. One was in fact Slave Lords; but not the exact capture scenario as written in the module. Half the party got away, the other half got captured; on which I then ran an A4-like escape scenario for the captured ones side-along with running the free ones so I'd know what they were doing. Lots of running from room to room for me as DM!

The other was when a single character exploring on her own hit a teleport trap that put her in a prison. As fate would have it, the captured PC was a Thief; she managed to pick the lock of her cell, release a few other prisoners, and they (against some very serious odds!) fought their way out from the inside and met the rest of the party just coming into the complex. I and the Thief's player played her situation out in an off-cycle session to a point where it seemed likely she'd meet the party; then she-as-player came to the main session and stood by until the party met her PC - which didn't take long, as pretty much all the main group had to do was walk up to the castle door and get inside.

If the captured group stay captured and don't or can't escape then it's easy: you just run the free group. I've had one of these: a chute trap sent a few PCs sliding down into a prison; some other PCs went down to rescue them and also got caught, leaving just two PCs free out of an original party of seven. I ran the free group until - long story - they too were captured at the request of the already-captured rest of the party!