What your invitation tells you
| Line in your email | What it means | Source |
|---|---|---|
| The length (“65 minutes”, “85 minutes”…) | The only official clue to which games you'll play. McKinsey: “The length of your Solve assessment is outlined in your invitation email” | MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab) |
| A deadline | Candidates report roughly 3 to 7 days to complete it. Your email is the authority | MCP (source: MConsultingPrep, McKinsey Solve (Imbellus Game) overview, opens in a new tab) |
| The link | Opens a tech check first. PC or Mac only; no iPad or phone | MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab) |
| A support contact | Problems during the test: gbil-support@mckinsey.com or live chat while it's happening. McKinsey says it can't reset afterwards | MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab) |
Decode the number
McKinsey doesn't say which games each length holds. Candidates report a consistent pattern:
Not sure of your length? Search your inbox for “Solve” and read the first paragraph of the invitation. If it truly isn't there, ask your recruiter; plan for 85 until you know.
The games in 30 seconds each
35 min
Redrock Study
Collect data into a research journal, calculate, complete a report, then answer standalone mini-cases (six in current versions)
The one thing to know: the flow runs one way: skip a number in Investigation and it stays skipped RTO (source: Road to Offer, McKinsey Redrock Study guide (updated September 2026), opens in a new tab)
~30 min (one source says 35)
Sea Wolf
At each of three ocean sites, build a pool of about ten microbes and pick three to treat it
The one thing to know: the average of each attribute across your three must sit inside the site's range; no single microbe has to CB (source: CaseBasix, McKinsey Solve full guide (updated August 2026), opens in a new tab)RTO (source: Road to Offer, McKinsey Redrock Study guide (updated September 2026), opens in a new tab)
20 min, 13 questions
Sustainable Futures Lab
Run a sustainability project: rank four opening actions, then make scenario calls on priorities, trade-offs and your team
The one thing to know: it's judgment, not arithmetic. How it's scored is not public MCP (source: MConsultingPrep, McKinsey Solve (Imbellus Game) overview, opens in a new tab)SGG (source: Solve Games Guide, McKinsey Solve 65 vs 85 minutes and SFL (updated September 2026), opens in a new tab)
varies
Ecosystem
Build a food chain that survives
The one thing to know: phased out in most locations since mid-to-late 2025. Old guides still teach it MCP (source: MConsultingPrep, McKinsey Solve (Imbellus Game) overview, opens in a new tab)
Clocks are as reported by candidates and prep sites.
Timing: book more than your number
- Each game starts with an untimed tutorial MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab)
- Read the objective slowly there; it costs you nothing
- Tutorials take roughly 5–10 minutes each (one provider's estimate) SC (source: StrategyCase, McKinsey Solve (updated September 2026), opens in a new tab)
- Block 2 hours for an 85-minute invitation, 90 minutes for 65
- Each game has its own time limit SC (source: StrategyCase, McKinsey Solve (updated September 2026), opens in a new tab)MCP (source: MConsultingPrep, McKinsey Solve (Imbellus Game) overview, opens in a new tab)
- Minutes saved in Redrock don't carry into Sea Wolf. Pace each one alone
- Every candidate gets different numbers MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab)
- Memorised answers are useless. Only method transfers
What's banned (McKinsey's words)
During Solve you may not “use applications, websites, AI tools, or pre-prepared notes” or “record or capture screenshots”, and you take it “alone, without assistance from others” MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab). McKinsey lists the consequences: “exclusion from consideration, rescinding of an offer, restrictions on future applications, or legal action.” Using AI to learn before the test is marked “Encouraged” MC (source: McKinsey & Company, Getting ready for your interviews (careers page), opens in a new tab).
The Solve FAQ doesn't mention calculators or scratch paper. McKinsey's assessment integrity page, which covers any assessment, allows pen and paper and bans a calculator. The sources are on how we teach.
What to do with the days you have
14 days
Week 1: percentages, weighted averages and chart reading, 20 minutes a day. Read one game's rules a day. Play the free Ecotopia Redrock study once to see the screens
Skip: full timed runs every day in week 1. Rules and math first
7 days
One timed run a day, a different game each day. After each run, write down the phase that cost you minutes. Protect 10 minutes for Redrock's cases
Skip: watching another walkthrough instead of playing
3 days
One full rehearsal at your invitation's length, on the laptop you'll use. Then fix only your weakest game
Skip: learning a new game from scratch
1 day
Run McKinsey's tech check on that machine and network. Charge, close other apps, book the quiet slot. Then stop practising
Skip: a late-night cram run
Test day
Read each tutorial's objective slowly. If something breaks, contact support during the test
Skip: anything that isn't the game's own tools
Seven common mistakes
- Collecting everything in Redrock. Solve reportedly records how you work as well as your answers. Decide what the later steps need, then click MCC (source: MyConsultingCoach, McKinsey Solve Guide (updated June 2026), opens in a new tab)SC (source: StrategyCase, McKinsey Solve (updated September 2026), opens in a new tab)
- Percent vs percentage points. 20% → 26% is +6 points and +30% relative. Answer choices often include both.
- Simple average where a weighted one is needed. Weight by the group sizes.
- Checking Sea Wolf microbes one by one. Turn the range into a sum band: a 5–7 range means the three values must add to 15–21.
- Starting Redrock's cases with 5 minutes left. Both published splits protect about 10 minutes for them RTO (source: Road to Offer, McKinsey Redrock Study guide (updated September 2026), opens in a new tab)SC (source: StrategyCase, McKinsey Solve (updated September 2026), opens in a new tab)
- Preparing for the wrong game. Ecosystem guides are out of date for most invitations.
- Reporting a tech problem after you finish. Support can help only while it's happening MF (source: McKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF), opens in a new tab)
Your next step
Your plan to your test is in your inbox: weekly at first, then one task a day in the last two weeks, and it stops when your test is done. Day 1 is free: the full Ecotopia Redrock study, 35 minutes on the clock, no sign-in. It's DrillCase practice material, not McKinsey's game.
Play Ecotopia on the clockFound a difference between this page and your invitation? Reply to any of our emails. We check every report and date the change.
Sources, all checked 23 Sep 2026
- MFMcKinsey & Company, Solve: McKinsey's Assessment Game FAQs (August 2025 PDF)
- MCMcKinsey & Company, Getting ready for your interviews (careers page)
- MCCMyConsultingCoach, McKinsey Solve Guide (updated June 2026)
- SCStrategyCase, McKinsey Solve (updated September 2026)
- HTCIHacking the Case Interview, McKinsey Solve: The Complete Guide (updated June 2026)
- SGGSolve Games Guide, McKinsey Solve 65 vs 85 minutes and SFL (updated September 2026)
- MCPMConsultingPrep, McKinsey Solve (Imbellus Game) overview
- RTORoad to Offer, McKinsey Redrock Study guide (updated September 2026)
- CBCaseBasix, McKinsey Solve full guide (updated August 2026)
- PLPrepLounge forum, McKinsey Solve game timing inquiry (coaches' answers, August 2026)
Independent practice. Not affiliated with McKinsey, BCG or Bain.