1.3 The 2020 Scrum Guide Is The Single Source Of Truth

The 2020 Scrum Guide Is The Only Authority

One Source, No Substitutes

The PSM I assessment is built directly on the 2020 Scrum Guide, written by Ken Schwaber and Jeff Sutherland and published free at scrumguides.org. It is the definition of Scrum, and it is deliberately incomplete by design — it describes the framework's boundaries, not a complete methodology. PSM I is not based on:

• Scaling frameworks such as SAFe (Scaled Agile Framework) or LeSS (Large-Scale Scrum)
• Complementary practices like Kanban, XP (Extreme Programming), user stories, or story points
• Organization-specific habits like "how my company does standups" or "our two-week release train"
• Earlier Scrum Guide editions (2017 and before)
• The Agile Manifesto, which Scrum is consistent with but is not defined by

If an answer option reflects common workplace practice but contradicts the Scrum Guide, the Scrum Guide wins. This is the most important mindset shift for the exam: you are being tested on the framework as written, not on pragmatic shortcuts your team may have adopted. A perfectly reasonable real-world practice ("the Scrum Master assigns tasks to keep things moving") is an exam trap because the Guide makes the Developers self-managing.

How PSM I Tests The Wording

Questions typically probe one precise idea at a time: who is accountable for what, which commitment attaches to which artifact, whether an event has a fixed time-box, and which empirical pillar a behavior supports. The framework is small enough to memorize exactly, and that is the expectation. Commit these structural facts to memory:

• 3 accountabilities: Product Owner, Scrum Master, Developers — together they form one Scrum Team.
• 5 events: the Sprint (a container) holding Sprint Planning, the Daily Scrum, the Sprint Review, and the Sprint Retrospective.
• 3 artifacts, each with a commitment: Product Backlog → Product Goal; Sprint Backlog → Sprint Goal; Increment → Definition of Done.
• 3 empirical pillars: transparency, inspection, adaptation — Scrum is founded on empiricism and lean thinking.
• 5 Scrum Values: commitment, focus, openness, respect, courage.

A frequent exam pattern gives a workplace scenario and asks what the Scrum Master should do. The correct answer almost always reinforces transparency (making reality visible), preserves self-management, or coaches rather than commands. Answers in which the Scrum Master makes decisions for the team, assigns work, or commits the team to a scope are usually distractors.

What Changed In The 2020 Scrum Guide

The 2020 edition is shorter (about 13 pages) and more focused than 2017. PSM I expects the current wording, and distractors are frequently built from the old terms.

The 2020 Guide also dropped the prescriptive three Daily Scrum questions (what did I do / will I do / impediments) — the Developers may run the Daily Scrum however they choose as long as it inspects progress toward the Sprint Goal. It removed the wording that the Sprint Backlog be a forecast plus a plan and instead framed each artifact around its commitment.

The three accountabilities (not roles)

• Product Owner — accountable for maximizing the value of the product resulting from the work, and for effective Product Backlog management.
• Scrum Master — accountable for the Scrum Team's effectiveness and for establishing Scrum as defined in the Guide; a true leader who serves.
• Developers — accountable for creating a usable Increment each Sprint and for adhering to the Definition of Done.

When an option uses "Development Team," "self-organizing," "servant-leader," or "responsible," suspect a 2017-era trap and look for the cleaner 2020 phrasing elsewhere in the list.

Why "The Scrum Guide Wins" Is The Whole Game

New candidates often resist this rule because their day job runs Scrum loosely. But PSM I is explicitly a test of the definition of Scrum, and the Guide states that Scrum's roles, events, artifacts, and rules are immutable — implementing only parts of Scrum is possible, but the result is not Scrum. The exam leverages this constantly. Consider a few realistic traps and the Guide-aligned answer:

In every case the workplace-pragmatic option is wrong and the Guide-faithful option is right. Train yourself to ask, on each question, "What does the 2020 Scrum Guide literally say?" rather than "What would my team actually do?" That single reflex resolves a large share of the assessment. The Guide is short enough — about 13 pages — that genuine memorization of its rules, not interpretation, is the winning strategy.