Here are suggestions in two RPG formats for a "Trial" type game:
In an espionage game, suddenly one morning a character is almost assassinated....by his own agency! He cannot get any effective answer why this happened after contacting his higher ups, who advise him he is now on a "shoot to kill" list. He is told that it is probably a misunderstanding and that it will be cleared up shortly, but until then, there is nothing the agency can do and the assassination attempts will continue. His allies/friends are told that they are not to assist their friend (they can choose to ignore this advice or not as they wish) and as a matter of fact they are also told to "shoot on sight" their friend (even though they cannot tell them exactly why the order has been given)!
This can continue in a series of adventures in the vein of movies like "North by Northwest" or "Mission Impossible 1" where the character, while being pursued by shadowy assassins, tries to discover who ordered his death for what reason. His friends can choose to aid him covertly or directly,or even attempt to kill him themselves! The final denouement after a series of adventures should lead to some surrealistic ending....the "kill" order was a computer glitch for someone with a similar name (whoops!) or the person issuing the command was a higher up that wanted revenge on the agent for some ridiculous slight years ago (a school rival that resented the character or a jilted girlfriend from high school), the more petty and absurd the reason the better.
You could even use this sort of scenario in a fantasy RPG game (like D&D). Much as in "The Trial", one morning while sleeping in a local inn someone knocks on the character's door. A notice is slipped underneath saying he is to appear for "final judgement" in front of a local lord in one week (or whatever time limit the DM wishes) or face death at the hands of his knights. Any attempt to find out what the character is accused of, or what this is about, is met with the same sort of situation as "The Trial".....lots of passing the buck, with no one sure what is going on, and handing the problem off to various other NPCs, with no useful advice ever given. To top it off everyone in the village starts avoiding the character, he gets kicked out of wherever he is staying with no one willing to put him up, no one will serve him in the local bar, no one will sell him anything, associated with him, etc. (this will also happen to anyone unfortunate enough to be identified as the character's friends or allies). NPCs will act like the character is "doomed", and tell him that everyone that has been summoned by the lord ends up executed. Soon the character and his friends notice they are being followed and spied upon by shadowy figures, who if they are captured or killed turn out to know nothing of why they were hired to follow and harass the character! Divination attempts of all sorts fail to reveal the nature of the character's dilemma, as time ticks away for the character to appear in front of the local lord for a reason he cannot fathom.
This would work especially well with lower level characters with few resources, and ones who would be justifiably afraid of a high level lord and his knights. Since the setting is fantasy, there could be unusual reasons behind the summons....perhaps the summons is a fake and instead an old enemy is using gold from a treasure trove to pay people to drive the character bonkers, including hiring random thugs to shadow the character and attempt to kill him. Perhaps the summons is real, the result of a jilted lover who is now the lord's consort and has persuaded her new beau to make the character's life miserable (or a hag or magical succubus that has enthralled the lord and sees the characters as future problems to her plans). The summons could be because of a mistaken identity, or a misinterpreted order ("Oh, sorry sir, the lord has summoned you here to give you a reward for that group of bandits you and your friend's stopped, not to execute you for treason! Silly scribe must have gotten these two proclamations mixed up, funny joke that eh?") The reason could be magical....an enemy mage has charmed the lord and the character's must break the spell, or the enemy could have the lord's child under thrall unless the lord carries through with the execution (making the characters have to find out what is going on then rescue the child). Above all the DM would have to make the circumstances confused and murky and sow real paranoia in the player...this wouldn't work with all players, but it could be a really tense and nail biting game if the DM pulled it off!