Following the success of the escape room game genre that launched in 2016, designers Michael Palm and Lukas Zach have created a twist on the genre with Undo, a concept that currently exists in three titles launched in early 2019 by German publisher Pegasus Spiele: Undo: Cherry Blossom Festival, Undo: Blood in the Gutter, and Undo: Curse from the Past, the title I focus on in the overview video below, mostly due to the strong typeface on the clue cards that make them easier to read on video.
The gist of each episode of Undo is that someone has died. People die all the time, of course, but for some reason you and fellow players, Weavers of Fate that you are, have taken particular interest in this person, so much so that you will revisit past events and meddle in those happenings to try to prevent this death.
You're not all-knowing, however. The past is laid out in eleven story cards (as well as one story card that takes place after the person's death), and over the nine rounds of the game, you encounter nine of these twelve story cards, piecing together what's happening so that when you're confronted with the A, B, and C choices of what should happen at the end of each story card, you make the best decision possible.
Based on my experience with each of these titles on review copies from Pegasus Spiele, each mini-scenario on a story card and its related choices spur lots of discussion among players, then you look at the fate card associated with your choice, e.g. 6C, to discover whether you've been assigned a 0 (meaning that you changed nothing about the person's fate), a positive number (which suggests a positive change), or a negative number (which suggests that you shouldn't meddle with such things because you're just making the situation worse).
After visiting nine locations in time, you sum the points on the fate cards, then look at the concluding elements to determine whether you saved the person. You also get to read a summary of events that brought the person to that critical moment as well as the most important elements in their past, the ones that ideally you will have switched onto a new track to undo the past.