McKinsey Solve Practice Guide: Red Rock, Sea Wolf & 2026 Changes

Looking for the full McKinsey process around Solve? Our McKinsey Solve guide covers what each module is, timings by invitation length, what comes after Solve, and the interview rounds. Run timed simulations of every module at the Solve practice page, or read the walkthroughs for Redrock Study, Sea Wolf, Sustainable Futures Lab and Ecosystem Building.

McKinsey Solve is an interactive problem-solving assessment. Candidates report differing task lineups and durations, including a Sustainable Futures Lab module in 2026. A guide that promises one fixed exam for every applicant is too confident.

Our McKinsey Solve practice hub offers timed simulations of every module on original content, including public worked examples, plus 65-, 85- and 95-minute full sittings.

Start with the official instructions

McKinsey says preparation is unnecessary and considers Solve alongside the rest of your application. Its public video shows Red Rock Island research, a journal, a provided calculator and report conclusions, followed by Sea Wolf database searches, sorting and microbe treatment selection. Both have guidance before timed work. Start with that video on the official Solve page.

Your invitation gives the assessment duration. McKinsey's Solve FAQ confirms untimed tutorials before each task, PC or Mac access, and no requirement for prior business knowledge or gaming experience. Reserve the time specified in your invitation, including its instructions for setup.

Which Solve games should you expect?

The evidence supports these distinctions as of September 2026:

In March 2026, separate firsthand threads described an additional scenario-based module, with one naming Sustainable Futures Lab and reporting an 85-minute assessment. A later publicly shared invitation specifies approximately 95 minutes, plus additional instruction time. These are individual reports, not a representative sample or an official schedule. They are enough to make a universal 65- or 85-minute claim unreliable. March candidate account, named Sustainable Futures Lab account, 95-minute invitation report.

Red Rock: investigate, calculate and explain

In our original data practice, the central challenge is choosing the right calculation from the available evidence. Arithmetic is only one part of that decision. Before calculating, identify the population, time period, unit and comparison the question asks for. A correct calculation using the wrong denominator still answers the wrong question.

Consider this original example. A project treats 240 of 600 samples in its first period and 330 of 750 in its second period:

• The treatment rate changes from 40% to 44%.
• That is an increase of 4 percentage points.
• Relative to the original 40% rate, the increase is 10%.
• The number treated rises by 37.5%, from 240 to 330.

All four statements are compatible. The wording of the question determines which number belongs in the answer. This is why our practice makes units and rounding instructions explicit and explains the denominator in the review. Our Redrock Study simulation runs the full format on one 35-minute clock: investigation with a research journal, analysis with a calculator that logs every result, a memo and chart report, and six mini-cases.

Use a journal selectively: keep a number with its label and unit, along with what you expect to calculate from it. Copying every visible number can make a small study harder to navigate. Before submitting a conclusion, check that it follows from the evidence rather than adding an unsupported explanation. An increase after an intervention does not, by itself, prove that the intervention caused it.

Sea Wolf: check the combination, not just each card

Our constraint practice uses three separate ideas: a team's numeric averages must satisfy stated ranges; at least one member must carry a required trait; and no member may carry a forbidden trait. These are explicit rules of our exercises. Always follow the instructions shown in your actual assessment if they differ.

For an original simplified example, suppose a three-member team's average resilience must be between 6 and 8, at least one member must have a filter trait, and none may have a toxin trait. Members with resilience values of 3, 7 and 11 average 7. The low and high values balance each other. Rejecting every individual value outside 6–8 would discard that valid numeric combination.

The trait conditions need separate checks. One filter carrier is enough under an “at least one” rule; three are unnecessary. A single toxin carrier fails the “none” rule even when every numeric average is perfect. A good numeric match cannot repair a forbidden trait.

Some July 2026 takers said their commercial Sea Wolf practice felt easier than the assessment and described difficulty fitting team averages to target ranges. That supports practicing complementary values and near-miss combinations. It does not prove that their candidate pools had no perfect solution or reveal the employer's grading formula. Firsthand difficulty discussion.

Our Sea Wolf simulation runs three sites in 30 minutes: profile two characteristics, sort ten microbes, build a pool of ten and choose three. Its review explains satisfied and missed checks using your actual pool and lists every 100% treatment that was reachable.

What about Sustainable Futures Lab?

Candidates describe a further task involving project scenarios, ambiguous information and choices about how a team should proceed. The March reports differ in how difficult and intuitive they found it. Firsthand SFL discussion.

Prep sources describe two versions. The 20-minute version on 85-minute invitations opens with two briefing screens, asks you to rank four candidate first actions, then presents twelve single-choice decisions in one storyline, each followed by a consequence screen. The 30-minute version on 95-minute invitations has you lead a four-person research team across four workstations for three simulated days; each day you explore with a few preset questions, assign researchers to stations, answer support requests and rate how each researcher is doing.

Our Sustainable Futures Lab simulation builds both on original environmental projects: Project Lead for the 20-minute format and Team Lab for the 30-minute format. The preferred answers are our own reasoning about each fictional scenario, and the review gives the rationale for every option rather than presenting a choice as McKinsey's key.

Ecosystem Building and Plant Defense

Ecosystem Building has left the default lineup but still appears in some versions. Our Ecosystem Building simulation gives you 39 original species, a terrain map, eight picks and one location, then plays back the eating order that decided whether your ecosystem survived. Plant Defense is retired; our Plant Defense simulation covers it for anyone reading an older guide.

How to use our practice

Start with the public worked examples. Then use the practice page to choose a module simulation, a full sitting or an untimed warm-up drill.

Each module simulation runs on that module's reported clock: 35 minutes for the Redrock Study, 30 for Sea Wolf, 20 or 30 for the Sustainable Futures Lab and 35 for Ecosystem Building. The full sittings combine them at 65, 85 and 95 minutes, the invitation lengths candidates report. The untimed warm-up drills let you examine a method without the clock.

A useful sequence is:

1. Learn the format. Read the module walkthrough and the untimed briefing, complete one simulation, and check the explanations even when your answer is correct.
2. Find the specific error. Separate misreading, choosing the wrong formula, arithmetic, overlooking a trait, and running out of time. Each needs a different adjustment.
3. Retry the weak skill. For percentage errors, state the denominator before calculating. For constraint errors, check averages and traits separately.
4. Use the full sitting for pacing. Notice where you stall and which work remains unfinished. Review accuracy and completion together.

Our scenarios, data and explanations are original.

Public examples and module walkthroughs are free, and each module simulation has one free attempt with an account. A McKinsey Solve pass covers this practice category only: replays of every module simulation and the full sittings for the selected period. It does not unlock other assessment categories.

How to read your practice results

McKinsey publishes no scoring formula, so ours is explained beside every item. Island Study also shows how you worked, such as which data points you saved and which answers came from the calculator, as feedback beside the checks rather than a hidden process score. We do not offer a supposed qualifying decile.

The useful questions are concrete: was the calculation correct, did the selection satisfy the requirements, and what remained unanswered? We report educational results under our own rules, without converting them into an official score. Treat any claim that a particular simulator result guarantees an interview with skepticism.

FAQ

Is this a complete McKinsey Solve simulation?

It runs a timed simulation of every module on original content, with worked reviews. Read the module walkthroughs before choosing a pass.

Is Solve always 65 minutes?

No. McKinsey's FAQ directs candidates to their invitation, and candidates report 65-, 85- and 95-minute invitations. Our full sittings match those three lengths.

Is the Ecosystem game definitely retired?

We cannot establish that for every role and location. A January 2025 candidate account included Ecosystem alongside Redrock and Sea Wolf. Follow your invitation and tutorials rather than treating a dated online account as a guarantee. If your invitation includes it, the Ecosystem Building simulation covers its rules.

Do I need to buy preparation?

No. McKinsey says preparation is unnecessary. Our worked examples and module walkthroughs are free, and each module simulation has one free attempt with an account; a pass is an optional way to replay them.

Can I use this practice, an AI assistant or saved notes during the real assessment?

No. McKinsey's integrity rules prohibit outside assistance, apps, websites, AI and prepared notes during Solve, except for an approved accommodation. They also prohibit capturing the assessment. Use preparation resources beforehand and close them before starting.

What if I have a technical problem or need an accommodation?

The official FAQ directs candidates to Solve support when a technical issue occurs and to their recruiter for accommodation requests. It does not support assuming that a poor result entitles you to an immediate retake.

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