Place a circle or sphere in the middle of a free space. Let the team gather around it. Explain that the circle is the center of approval: If they agree to a statement they should move towards it, if they don't, they should move as far outwards as their degree of disagreement. Now read out statements, e.g.
I feel I can talk openly in this retrospective
I am satisfied with the last iteration
I am happy with the quality of our code
I think our continuous integration process is mature
Watch the constellations unfold. Afterwards ask which constellations were surprising. This can also be a closing activity (#53).
Write down what you can never ever say out loud Source: Unknown, via Vanessa
Do you suspect that unspoken taboos are holding back the team? Consider this silent activity: Stress confidentiality ('What happens in Vegas stays in Vegas') and announce that all notes of this activity will be destroyed in the end. Only afterwards hand out a piece of paper to each participant to write down the biggest unspoken taboo in the company. When everyone's done, they pass their paper to their left-hand neighbors. The neighbors read and may add comments. Papers are passed on and on until they return to their authors. One last read. Then all pages are ceremoniously shredded or (if you're outside) burned.
Prepare a flip chart with 3 columns titled 'What', 'Who', and 'Due'. Ask one participant after the other, what they want to do to advance the team. Write down the task, agree on a 'done by'-date and let them sign their name. If someone suggests an action for the whole team, the proposer needs to get buy-in (and signatures) from the others.
Prepare 3 flip chart papers titled 'Helped', 'Hindered', and 'Hypothesis' (suggestions for things to try out). Ask participants to help you grow and improve as a facilitator by writing you sticky notes and signing their initials so that you may ask questions later.