Inspired by this thread about 'Excessive Force in Campaign over here, I wanted to start sharing ideas on Court Martial episodes. They are part of most of if not all of the Trek series (I am not entirely sure about ENT/DIS, though) and, as @aramis put it in the linked post, “can be excellent drama”.
I once did a some kind of special ‘Court at the Court’-adventure with my D&D group: There was a conflict in a little village that escalated very quickly into a full-grown battle – with the village-folk on the one and seasoned adventurers on the other side. Within a few rounds, the village had to mourn 8 or 9 casaulties (sources differ. 
). With a bounty set upon the heads of the perpetrators, some obfuscation by the party’s rogue and several plot-twist, months in game-time (and almost a year in reality-time, iirc) later, the incident finally came back to the PCs. The one who started the escalation was dragged before the Queen and her advisors and had to answer for his crimes.
Since this incident had become first a minor and then even a major arc of the campaign, I wanted the session of the court to take a full gaming session with everyone involved. Since there was only one accused (if convicted, the others would have followed immediately or, at least, very soon), several PC witnesses and even von player, who wasn’t there during the incident, I decided to set it up as follows:
The player of the accused PC would stay in his character the whole time. The player of the then-absent character would also stay in his character. Since this character happend to be a paladin, I decided that the queen would name him the criminal defence. The other players would play their respective characters when they would appear as witness before court. In the meantime, they were allocated NPC – the queen’s advisors and fellow judges and one even the accuser. I fleshed out one-page NPC with own hidden motivations or agendas and a mini-game of ‘shifting attitude’. Basically, when certain facts of the case would be mentioned by someone, some NPC-judges would get a roll to see if this fact would affect their attitude towards the accused, either positively, or negatively. For example, if the PC would confess that he was the first to draw his weapon, one judge could be affected positively (for he honoured the honesty of this confession), while another could be affected negatively (for he condemned the unnessecary escalation followed by bloodshed). Of course, I would take over their NPC during their PC’s appearance before court, to prevent exploitation of knowledge of the NPC’s hidden agenda.
Also, the Paladin, acting as criminal defence, could try to influence the judges with well-placed diplomacy-rolls (one per judge) that could either have a positive effect or prevent a negative effect on success.
After all witnesses were heard and the defence had made their final statement, every judge were to announce their ruling, depending on (again, individual) tables, relating the ruling to the attitude (friendly, unfriendly, hostile etc.) towards the accused.
Despite the “mini-game” I devised, the session turned out very roleplay-heavy and very dramatic. Despite there was a real chance of the PC losing his head (and the player losing his character), everything turned out well and it was one of the most intense sessions, I had in years.
I think, if I ever were to court-martial some of my PCs, I would consider adapting this method for STA. I would name appropriate traits and even values to the judges to reflect their inner motives. Then I would make the defendants try to ‘hit’ these values in a way good for them. Also, the attitude (including preferred sentencing ranging from acquittal over harsh disciplinary action and demotion to expulsion from Starfleet) could be reflected by traits.
The rules for social conflict would be used to present arguments to the court and convince the judges of the innocence (or guilt) of the accused and, thus, changing their traits. I would possibly have to restrict the trait-establishing power of Momentum-use for a while, but in principle, I imagine this to work.
My experience worked very well with a player, who knew that his character made a terrible mistake (while his character did not share this view to the whole extent) and a group who was experienced enough to a) keep tension high (even when it was clear to me that the PC would suffer no permanent harm, everyone kept a poker-face and the player in question had a very intense session), and b) would not have taken offence in ‘losing’ the proceedings.
Making my final remark, I would suggest using court-martial episodes only, when the group is very clear about the guilt or innocence of the character. So, if the character was to be found guilty, he either deserved the ruling or the session would spark new material for another story arc about reversing the judgement (same goes for innocence, respectively). I would encourage my fellow GMs to point this out clear from the beginning: that there would be no rail-roading and that the ‘wrong’ outcome would just start another story arc and would not need to be a permanent set-back for the character(s) but a possibility for character growth.
Having finished quite a wall of text, I would now be very curious on how you would take such an episode. And even more, if you could give me any ideas on how to use a Court Martial episode to tell a story/case/crime in hindsight (as it was done e.g. in the Voyager episode “Ex Post Facto”). This is something I really would want to do!
) confirmed this a few days/weeks ago, but could not find their post.