MNblockhead
A Title Much Cooler Than Anything on the Old Site
So you start with 4 plot points. As the adventure progresses you have more opportunities to gain more and spend plot points. After every major day or night scene, the party gains 1 plot point. If they bungle something, they get 2 plot points. You use plot points to set up complications and change routines or the actions of a group or enemy.There are lots of ways you could houserule it. But haven't some from WotC means a standard set that everyone knows. Of course, if it's like the ship combat rules, then the official rules suck.
How many preparation points do you get? Is it based on class, level, gold expenditure or some sort of pre-heist quest completion? Are they individual, or a shared pool? Can I use preparation points in non-heist situations? Some serious game development skill needs to be applied in order to get a good well balanced generally applicable system. The idea on it's own isn't enough.
The preparation phase has six scenes (three days, each with a day and an evening scene), which involves recruiting factions, performing reconnaissance, and procuring necessary items, etc.
Routines are things the DM sets up. The adventure recommends using adventure cards to organize routines. The players spend plot points to assign routines to enemy and company cards.
You also get a contingency plan token that can be spent if something goes wrong.
I haven't thoroughly read the adventure and the plot, routine, and contingency rules are kinda spread throughout the text. But I can see pulling out the mechanical bits and homebrewing a good caper/heist subsystem for 5e with it. Thanks to @Ruin Explorer for the recommendation!