Most formats above are variations on the same five-phase skeleton from Agile Retrospectives (Derby & Larsen): set the stage (get everyone talking early), gather data (facts and feelings on the board), generate insights (find the patterns), decide what to do (a few owned actions — not ten), and close (appreciate, and check the retro itself). Rotate formats now and then: the moment a retro becomes a ritual, it stops producing surprises.