## Definition **Three Amigos** is the practice of having business, development, and test specify a story *together*, in one conversation, before implementation begins. The output of the meeting is not a sign-off — it is the set of acceptance criteria that will drive the build. ## Three perspectives, one spec Each seat catches what the others miss: | Amigo | Brings | Blind spot they cover | |---|---|---| | Business | The goal, the value | "Why are we building this?" | | Development | Feasibility, cost | "That's three weeks, not three hours" | | Test | Edge cases, failure modes | "What happens at zero? At negative?" | Specify a story with only one or two of these and the gaps ship as bugs. Gojko Adzic's point in [[Specification by Example - Gojko Adzic]] is that the conversation itself produces shared meaning: "everyone shares responsibility for the right specifications." Ownership is collective, not handed off down a line. ## The output is acceptance criteria The meeting is not done when everyone agrees verbally; it is done when the agreement is written as concrete examples — ideally as a [[Gherkin Scenario]] each amigo can read. This is the connection to [[Specification by Example]]: the conversation generates the examples, and the examples outlive the conversation. ## The fourth seat In the agentic era a fourth participant joins the table: the agent. Its role is not to replace any amigo but to change the *tempo*. The agent drafts candidate scenarios fast — dozens of edge cases, boundary values, error paths — and the three humans switch from authoring to *challenging*. Humans become editors of the agent's proposals instead of blank-page authors. This works because generating scenarios is cheap and judging them is the expensive, human part. The agent does the cheap part at scale; the humans keep the [[Verifier Independence]] that makes the criteria trustworthy. ## Failure modes - **The async amigos**: criteria passed through tickets instead of conversation — you lose the friction that surfaces disagreement. - **The rubber-stamp amigo**: a seat that attends but never challenges — now the agent's draft is law, which defeats the point. - **Goal skipping**: arriving with a solution already fixed, instead of [[Deriving Scope from Goals]]. ## Related - [[Specification by Example]] - [[Gherkin Scenario]] - [[Deriving Scope from Goals]] - [[Verifier Independence]]