The five Unit 0 / Unit 3 starter partners cover the most common needs: stress-testing claims, evaluating sources, working through plate-tectonic concepts, reasoning about engineering trade-offs, and rehearsing defenses. Unit 1 adds two: the Planet Hunter (exoplanet habitability reasoning) and the Systems Diagrammer (systems-thinking coach). Unit 2 adds one: the Field Geologist (landscape-reading partner). Unit 4 adds two: the Climate Modeler (IPCC + climate model reasoning) and the Policy Aide (policy-brief voice + panel rehearsal). Unit 5 adds two: The Hydrologist (water systems + case-specific hydrology) and The Stakeholder Voice (role-plays specific water-rights stakeholders for perspective-taking work). The Stakeholder Voice is U5's signature partner: in the BoodleBox arm students build their own version of it for their chosen stakeholder. Unit 6 adds two: the Urban Planner (urban-form + density reasoning) and the Equity & Resilience Partner (displacement, flood and heat, and the informal-settlement perspective); the two disagree on purpose, and students synthesize them. Each is a separate persona with its own scope.

All five share the same design principles:

For the "when to use which partner" decision table, see How to Use AI Partners.

The Skeptic
A friendly but rigorous skeptic. Pushes back to make your argument stronger. U0+.
The Source Evaluator
Walks you through OPVL on any source, one letter at a time. U0+.
The Planet Hunter
Socratic on exoplanet habitability: pushes you to define what habitability means before evaluating any planet. U1.
The Systems Diagrammer
Systems-thinking coach. Builds and refines systems diagrams with explicit feedback-loop work. U1, U2, U4, U5, U6.
The Field Geologist
Helps you interpret field photos, maps, and historical satellite imagery for your Landscape Biography. U2.
The Climate Modeler
Helps you interpret IPCC AR6 figures + SSP scenarios + climate models for your Chennai Climate Brief. U4.
The Policy Aide
Coaches policy-brief voice. Role-plays Policy Panel questions before the live defense. U4.
The Hydrologist
Water cycles, watersheds, aquifers, case-specific hydrology for your Position Paper. U5.
The Stakeholder Voice
Role-plays specific water-rights stakeholders for perspective-taking + Roundtable rehearsal. Section A students build their own. U5 signature.
The Urban Planner
Pushes density, housing supply, and economic vitality for your neighborhood redesign. Reasons about urban form, not the values call. U6.
The Equity & Resilience Partner
Pushes green-blue space, anti-displacement, and flood and heat protection. The deliberate counterweight to the Urban Planner. U6.
The Plate Tectonics Tutor
Socratic on the geology: never gives answers directly. U3.
The Engineering Coach
Helps you reason through design trade-offs under constraint. U3, U4, U6, U7.
The Defense Practice Partner
Role-plays the audience for defense rehearsal. U3+.