The Effort and Pain is a filtering activity to help the participants prioritize the retrospective items to be worked on.
Running the activity
1.Draw the Effort versus pain graph with the two axis: Effort on the Y axis, Pain on the X axis.
2. Instruct the participants to place the post-its in relation of each comparatively (e.g. this one requires higher effort that that other one, and is causing less pain)
3. Look for the items with high return (high pain, low effort)
This activity is inspired on Fabio Pereira post on Technical Debt Wall Retrospective. It is very effective for filtering out the items, prioritizing on the ones with higher return.