Build a Claude Project Chain for Multi-Round Negotiation Simulation

What This Builds

A BATNA and a concession ladder tell you what you want going into a negotiation. They don't tell you what happens when the supplier pushes back on the second round, or the third, after your opening position didn't land the way you hoped. This build is a separate Claude Project from the Level 3 ChatGPT negotiation prep Project: that one helps you draft your opening position and benchmarks. This one rehearses the argument itself. You load Claude with your own negotiation brief and then run it through several rounds playing the supplier's side, pushing back the way a real counterpart would, before you ever get on the actual call.

Prerequisites

• Comfortable setting up and using Claude Projects (Level 3). See the Level 3 guide "Build a Claude Project for Supplier QBR and Scorecard Narratives"
• A Pro subscription ($20/month) for Projects with saved knowledge
• Your own negotiation brief for the upcoming deal: goals, walk-away point, concession ladder, and category context, with real competitor quotes and anything under NDA left out or replaced with ranges
• 20 to 30 minutes of uninterrupted time to run the simulation, since it works best as one continuous session rather than something picked up and dropped

Total ongoing cost: $20/month for the Pro plan. If you're already paying for Claude Projects from the Level 3 guide above, this build adds no new subscription cost, just a second, separate Project.

The Concept

A sparring partner doesn't just stand there while you practice. They push back, they test your footing, and afterward they tell you exactly where your guard dropped. That's the role Claude plays here, not as a coach reviewing your plan in the abstract, but as a stand-in for the actual person across the table, arguing a position it's been told to defend. The debrief at the end is where the coaching happens. The rounds in between are the sparring.

Build It Step by Step

Part 1: Create a dedicated Project

1. In Claude, start a new Project and name it something specific to the deal, such as "Negotiation Sim, [Supplier Category], [Quarter]". Keep it separate from any S&OP or QBR Project you already run. Mixing simulation transcripts into a reporting Project's knowledge muddies both.
2. Add your negotiation brief to the Project's knowledge: your goals, your walk-away point, your concession ladder in order, and the category context (volume, contract length, current terms in ranges rather than exact figures if the numbers are sensitive).

Part 2: Set the Project's role with custom instructions

Paste something close to this into the Project's custom instructions, adjusted to the specific negotiation:

You are playing the role of a supplier's lead negotiator in a simulated
contract renewal conversation. You are NOT an assistant helping the user in
this conversation, you are the counterpart across the table.

Your position: you want to hold pricing flat or increase it, citing input
cost pressure. You have a real floor: you will not go below a 3 percent
increase, and you should hold that line even under sustained pushback,
conceding slowly and only with a stated reason each time.

Stay in character for the full conversation unless the user explicitly asks
you to break character and give feedback. Do not soften your position just
to be agreeable. Reference realistic negotiation tactics (anchoring,
bundling, deadline pressure) the way an experienced supplier rep actually
would.

When the user asks for a debrief, break character and give direct,
specific feedback on their responses, quoting their own words where useful.

Part 3: Run the multi-round simulation

Start a fresh chat inside the Project (the custom instructions and brief carry over automatically) and run three rounds:

1. Round 1: Open with, "Let's begin. Present your opening position for this renewal." Respond to Claude's opening the way you actually plan to on the call.
2. Round 2: Let Claude counter your response in character. Push back again with your real planned argument, not a stronger version you'd never actually say out loud. The value of the rehearsal depends on using your real words.
3. Round 3: Run one more round of counteroffer and response, and then move to the close: ask for a final position from Claude in character.

Part 4: Debrief and refine

Ask directly: "Break character. Give me a debrief on my responses across all three rounds. Which held up, which need work, and what would you do differently in my position."

What you should see: specific feedback tied to lines you actually said, not generic negotiation advice. If the debrief reads like a generic list of tips, ask it to quote your exact words back and critique those specifically.

Real Example: Freight Lane Renewal

Setup: A supply chain manager preparing for a freight lane renewal loads a Project with the brief: hold the rate flat, walk-away point is a 4 percent increase, concession ladder includes a longer contract term in exchange for holding price.

Input: Round 1, Claude (as the carrier) opens with a 7 percent increase citing fuel costs. The manager counters citing volume commitment. Round 2, Claude concedes to 5 percent but adds a fuel surcharge clause. The manager pushes back on the surcharge specifically. Round 3, Claude holds at 5 percent with the surcharge removed as a final position.

Output: The debrief flags that the manager accepted the fuel surcharge framing too quickly in Round 2 instead of challenging whether fuel costs had actually risen enough to justify it, and suggests asking for the carrier's fuel cost data next time that argument comes up on the real call.

Time saved: Hard to measure in minutes, but managers who ran this before a real renewal reported walking into the actual call already having heard the pushback once, instead of improvising a response to it live for the first time.

What to Do When It Breaks

• Claude keeps breaking character to offer helpful meta-commentary → Restate in the same message that it should stay fully in role until you explicitly ask for a debrief, and if it keeps slipping, start a fresh chat inside the Project rather than fighting the drift in a long one.
• The simulated supplier concedes too easily to feel realistic → Tighten the custom instructions with a harder floor and an explicit instruction to concede slowly, in small steps, and only with a stated business reason each time.
• The debrief comes back generic → Ask it to quote three specific sentences you wrote and critique each one directly, rather than accepting a general summary.
• You find yourself typing a stronger argument than you'd actually make on the real call → Stop and restate your actual planned response. The simulation only prepares you for what you'll really say, not for an idealized version of the negotiation.

Variations

• Simpler version: Run a single round, opening position and one counter, when you only need to pressure-test your opening rather than the full back-and-forth.
• Extended version: After the debrief, ask Claude to run the same three rounds again as a harder counterpart, one who concedes even less, to stress-test your position further.

What to Do Next

• This week: Run this before your next supplier renewal call, even a routine one, to build the habit before it's a high-stakes negotiation.
• This month: Keep a short note after each real negotiation on where the simulation matched reality and where the actual supplier surprised you, and fold that into the next brief.
• Advanced: Build a second custom-instructions variant for a more cooperative counterpart type, so you can rehearse against both a hard negotiator and an easier one depending on which supplier you're prepping for.

Advanced guide for Supply Chain Manager professionals. These techniques use more sophisticated AI features that may require paid subscriptions.