Spot the difference

A game for teaching about the impact of Batch Size on code commits, code reviews, and testing activities


This game intuitively teaches people about batch size and complexity, and its impact on commit size, deployment size, code reviews and testing activities within Continuous Delivery and Trunk-based development. When people are having fun learning is more effective, and when someone realises a solution themselves then they are more likely to successfully implement it.

We’ve created this game and licensed it under a creative commons license for coaching situations and workshop. Two copies of the game are available so people can’t spoil the game by copying each other.

The contents:

Within this game download you will find 5 pages. The first page will have 16 differences between the 2 images shown, the other 4 will have 4 differences each.

The first page represents a large batched sized item, and the final 4 pages represent small batched items of work, and cross the 4 they have the same complexity as the first sheet (Large batch size).

The rules:

  • Give everyone participating 1 copy of the game.

  • Place the first sheet in front of the participant facing up. Replace the remaining 4 sheets face down in front of the participant (You don’t want them to see the last 4 sheets).

  • Give the participants 10 minutes to find the 16 differences on the first page. Very few, if any, participants will find all 16 differences.

  • Get the participants to turn over the next sheets and work through all 4 in order to find all 16 differences (4 differences per page). Most people will find the differences within 5 minutes.

  • Once the game has been completed, run a debrief discussing the complexity and batch size in the context of the concept you are teaching.


Looking for other tools to help the team on their BDD journey?