So I had a wild idea, inspired by a friend, for my next scenario. A 24-hour time loop in Groundhog Day/Window of Opportunity/Majora's Mask style.
Essentially, the PCs will be caught in the effect of a spell gone wrong, which will have them reliving the same 24 hours over and over until they figure out what's starting it, and I'm planning to make it a hell of a day--in the first iteration, I'm planning to have some huge tragedy happen in front of each of them that they'll later be able to stop.
The plan is to run through the day quickly in the first session of the scenario--issue a lot of compels to speed things along and keep them moving so they don't dwell too much. Then start the next session exactly the same way, and from that point on, divide the scenario into discrete periods of time and let them 'save' their progress.
So the first thing that's planned to happen is one PC's boss is going to go out, run into ghouls, and be brutally killed before that PC can get there. And in subsequent sessions, he'll be able to relive that, do things differently, and then when he gets through it in a satisfactory way, we'll 'save' the day's progress at that point, with the assumption that the character repeats what he did the one time things went well.
I think this could end up being a really awesome scenario if I can pull it off. I've more or less got the plot of the day scoped out, but I'm interested in hearing if anyone has ideas for how to pull it off mechanically and structurally.
Well what's the end condition? How do they break the loop?
I would run it like a mystery game. A set of clues that lead to the bad guy. Follow the rule of three. At least three clues to each subsequent clue. At least three clue paths to follow to get to the result. Map it all out in a flow chart. Figure out how many game sessions you want it to take, Assume one major clue per game session and give yourself one that can be given away as a freebie and a hidden one you can stick in at the end if you need to make things easier or harder. Make it vital that they have each, so even if they figure out what's going on, they can't do anything about it till they have enough clues.
Example
My exit condition would be a ritual. They need 7 items for the ritual. Each game session they learn how to get one item. Within the first 30 minutes of each session plant a story hook leading to a clue. If they bite, lead them along as they find their way to the item they need. If they don't bite, leave the next hook. Keep dangling things till they figure it out. On the last session, they skip all of the problems that made it hard to find the item the first time, grab them, assemble, say bob's your uncle, and break the spell.
It would take 7-9 sessions. 1 to have them fail miserably and figure out what's going on. End that session with the start of the next day. 5-7 to figure out what's going on and what they need. Use the second session to let them explore and figure out how to prevent the failures they had the first time, give them the ritual, and if time, the first item.
Session 3-6, clue hunt. If they manage to get all 7 by then move on to the ritual. First 15 mins to an hour is saving people and getting items. Then as the ritual starts, move them out of time. Introduce Big Bad. Explain if they die here they really die. They try to get the ritual off while things try to prevent it. That should take between 1-2.5 hours. I would break it up into several mini encounters. A true fight till the bad guy is taken out or concedes, then maybe a chase, Some sort of slower challenge maybe a social combat or a riddle/mini mystery/puzzle. Finally the last fight, where bad guy and maybe minions attack. Some have to protect others, while they channel energy. They win, do post fight wrap up.
If they don't have all the clues by 7, introduce the bad guy, start the ritual. Have him harry them as they collect the last pieces, and start ritual as soon as they do. Skip the mega encounter session and just go right to casting while he tries to kill them.
