Fibonacci Flat Sequence
Fibonacci Flat (0, 0.5, 1, 2, 3, 5, 8, 13, 20, 40, 100) extends the classic Fibonacci deck in two directions. At the low end, the 0.5 card captures work that deserves a point but barely — a one-line change that still requires a PR review, a merge, and a deploy. At the high end, the 20/40/100 cards replace Fibonacci's 21/34/55 with rounder numbers and a deliberate ceiling: 100 does not mean "a very large story" — it means "this is not a story, it is a project." Playing 100 is a signal to the Product Owner, not an estimate. The middle range (1–13) behaves identically to Fibonacci, so teams familiar with the standard deck adapt quickly.
Cards: 0, 0.5, 1, 2, 3, 5, 8, 13, 20, 40, 100.
How to use Fibonacci Flat Sequence in planning poker
Use this deck exactly like Fibonacci, with two additions to your facilitation vocabulary. When someone plays 0.5, confirm: "Is this genuinely trivial, or are we underestimating the blast radius?" One-line changes in complex systems often have larger testing or deployment implications than they appear. When someone plays 100, treat it as a story-splitting request, not an estimate — stop the round and discuss decomposition before voting again. The 20/40 range is useful for stories that feel larger than a 13 but do not yet warrant splitting: they carry high uncertainty, and the large number signals that uncertainty explicitly.
Example tasks and point mappings
0.5: Update a single environment variable, fix a UI text typo in a single component. 1: Add a configuration toggle, adjust a logging level. 5–13: Same as standard Fibonacci — new API endpoint, screen with auth, module refactor. 20: Feature with multiple moving parts and unclear dependencies. 40: Multi-week work that probably should be split but the team cannot agree on how yet. 100: Rewrite the authentication system, migrate to a new database — not a story, return to the PO.
When to consider a different deck
New teams: the 0.5 card triggers debates about what counts as "barely a task," and 100 can be used as a passive-aggressive protest vote rather than a genuine signal. Teams using Jira's story point field may find 0.5 maps awkwardly (Jira rounds to integers in some views). If you do not need the extremes, standard Fibonacci is simpler.
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