Rules

The rules of the game are simple :

• Each participant gets a deck of estimation cards.
• The moderator (usually the product owner or an analyst), presents one user story at a time
• The product owner answers any questions the team might have.
• Each participant privately selects a card representing his or her estimate.
• When everybody is ready with an estimate, all cards are presented simultaneously.
• In the (very likely) event that the estimates differ, the high and low estimators defend their estimates.
• The group briefly debates the arguments
• A new round of estimation is made.
• Continue until consensus has been reached.
• The moderator notes the estimate, and the group continues with the next user story.

Why use Planning Poker ?

• It ensures everybody partitions in the estimation
• It  avoids 'coloring' of the estimates by a few key members of the team
• It speeds up the estimation process
• It is fun!

References

Mike Cohn, Agile Estimating and Planning, Prentice Hall
PTR, Upper Saddle River, NJ, 2005.
Read Chapter 6: Techniques for Estimating online.

J. W. Grenning, Planning Poker, 2002, http://www.objectmentor.com/resources/articles/PlanningPoker.zip.

An Empirical Study of Using Planning Poker for User Story Estimation
Proceedings of AGILE 2006 Conference (AGILE’06), Nils C. Haugen, Objectnet as