No one expects the ______________

The reddit posting "7th Sea Second Edition and the Tyranny of the Perfectly Expected" goes into a rather looooooooooong discussion of the lost value of the unexpected. I agree with much, how do you get that movie film moment when the Hero thinks they have succeeded, and then look down to find themselves shot or impaled, then the villain laughs takes the shiny thing, and escapes just as the rest of the group rushes in to get their companion to direly needed medical attention?