The McKinsey Solve Game, also called the Problem Solving Game (PSG), the McKinsey Digital Assessment, or by its old name Imbellus, is McKinsey's gamified screening assessment. Based on candidate reporting reviewed by PSG Cracked through May 2026, current invitations are typically either 65 minutes with Redrock and Sea Wolf, or 85 minutes with Redrock, Sea Wolf, and Sustainable Futures Lab. McKinsey reviews the result alongside the rest of your application, rather than treating it as a standalone pass mark. This guide explains the current format, how the games compare, what scoring really tells you, and where to go next based on your invitation.
Key takeaways
- McKinsey Solve, the Problem Solving Game (PSG), the McKinsey Digital Assessment, and the older name Imbellus all refer to the same gamified screening assessment. "The McKinsey Game" is a colloquial label.
- As of May 2026, two invitation lengths are common: the 65-minute version with Redrock Study and Sea Wolf, and the 85-minute version that adds Sustainable Futures Lab.
- Per-game timers are 35 minutes for Redrock, 30 minutes for Sea Wolf, and 20 minutes for Sustainable Futures Lab. Each game has its own clock, so use your invitation email to confirm the length you should prepare for.
- Solve is one input into the screening decision. McKinsey reviews it together with your CV and the rest of the application.
- Ecosystem Building, Ocean Cleanup, and Plant Defense are legacy games. They are not in current standard 2026 invitations, but their names still appear in older guides and candidate forums.
- The right next read depends on your situation: invitation length, target game, score anxiety, or how much prep time you have left. Use the routing table near the end to choose the next guide.
What is the McKinsey Solve Game?
McKinsey Solve is the firm's screening assessment for consulting roles. McKinsey describes it on its official digital assessment page as a game-based exercise used during the application process to evaluate problem solving, data interpretation, and decision making.
The assessment goes by several names. "Solve" is the current McKinsey-branded term. "PSG" is short for Problem Solving Game and is still common in candidate forums. "Digital Assessment" is the formal label McKinsey uses on its careers site. "Imbellus" is the legacy name, taken from the company that originally built the platform before McKinsey rebranded it. "The McKinsey Game" is a colloquial catch-all you will see on Reddit and other forums. They all describe the same test.
For readers who came in through the legacy name, the Imbellus game article covers the naming history in detail. The rest of this guide uses "Solve" as the canonical term.
Where Solve fits in the McKinsey hiring process
Solve is a screening step. Most candidates receive their Solve invitation after submitting their application and before interview invitations are finalized. The assessment is not a standalone pass-or-fail filter. McKinsey's Solve FAQ updated August 2025 states that Solve performance is considered alongside the rest of the application.
In practical terms, a strong Solve run reinforces a strong application, and a weaker Solve run is read in the context of your CV, cover letter, and interview signal. Treat the score as one signal inside the broader application review. No single number tells the whole story.
Which games are in the McKinsey Solve assessment in 2026?
As of May 2026, Solve usually appears in one of two invitation lengths. Each game runs on its own timer, so finishing one game early does not give you extra minutes on the next.
| Game | Timer | What it is | Who sees it |
|---|---|---|---|
| Redrock Study | 35 min | Data-interpretation task built around an island ecology study | Core current invitation game |
| Sea Wolf | 30 min | Constraint-based optimization across three contaminated ocean sites | Core current invitation game |
| Sustainable Futures Lab | 20 min | Text-heavy judgment scenario with a small team | 85-minute invitations |
A few details matter for prep. Redrock and Sea Wolf are the consistent core in current invitations. Sustainable Futures Lab (often shortened to SFL) is the third game, but only on 85-minute invitations, and the regions where candidates report seeing it are still expanding.
Older guides and candidate forums often mention Ecosystem Building, Ocean Cleanup, or Plant Defense. None of those are in current standard 2026 invitations. They are covered in the Legacy games section later in this article so the naming confusion does not get in the way of your prep.
How long is the McKinsey Solve assessment?
McKinsey's current Solve invitations come in two main lengths.
- 65-minute Solve. Redrock Study (35 min) plus Sea Wolf (30 min). Some candidates still receive this shorter invitation.
- 85-minute Solve. Redrock Study (35 min) plus Sea Wolf (30 min) plus Sustainable Futures Lab (20 min). This is the longer invitation and appears in a growing list of regional rollouts, including Germany, the Middle East, Southeast Asia, the United States, and Canada based on candidate reports through April 2026.
Older articles and forum threads sometimes reference 70-minute, 90-minute, 100-minute, or 110-minute Solve formats. Those numbers reflect previous years of the test, when Ecosystem Building was still part of the standard mix. They do not describe the current assessment.
Use your invitation email to decide what to prepare. McKinsey's August 2025 FAQ states that the total length of your Solve assessment is outlined in your invitation. If your invitation says 65 minutes, prepare for Redrock and Sea Wolf. If it says 85 minutes, add Sustainable Futures Lab. Do not plan around what your friend received last cycle.
Each game has its own timer, and the timers do not pool. Finishing Redrock with five minutes to spare is good for your Redrock score, but those five minutes do not transfer to Sea Wolf or SFL. That separation matters when you build your practice plan, because each game rewards a slightly different kind of reading and pacing.
How the three current games compare
The current Solve mix is varied. Redrock leans on quantitative reasoning, Sea Wolf on constrained optimization, and Sustainable Futures Lab on judgment under uncertainty. The cross-game comparison below is a useful planning shortcut.
| Game | Timer | Primary reasoning skill | Math / text load | What to practice |
|---|---|---|---|---|
| Redrock Study | 35 min | Data interpretation under structure, plus chart and report communication | Heavy on numbers and exhibits | Percentage and ratio fluency, calculator habits, chart selection, exhibit reading |
| Sea Wolf | 30 min | Constraint-based optimization and trade-off reasoning | Light arithmetic, heavy comparison | Filtering options, three-number averages, edge-range awareness, trait penalties |
| Sustainable Futures Lab | 20 min | Narrative judgment, team coordination, pressure reading | Heavy text, no calculation | Reading dense scenarios, weighing trade-offs, staying consistent across decisions |
The practical takeaway: each game rewards a different habit. A candidate who is comfortable with numbers may move quickly through Redrock and still struggle with the judgment calls in Sustainable Futures Lab. A candidate who is great at reading scenarios may underperform on Sea Wolf because the optimization rhythm rewards fast, structured comparison. That balance is why a single afternoon of practice usually is not enough.
A short look at each current game
Here is a quick orientation for each of the three current Solve games. Full mechanics, walkthroughs, and worked examples live in the dedicated guides linked under each one.
Redrock Study (35 minutes)
The Redrock Study is the data-interpretation task inside Solve. You step into the role of a junior analyst working through an island ecology study. The setting is RedRock Island, with subjects that rotate between runs. Past examples include wolf packs, plant biomass, reservoir capacity, and migration patterns, and the underlying workflow stays consistent regardless of which subject you receive.
Redrock has four phases grouped into two parts. The Study part runs through Investigation (read the brief and pull useful values into the Research Journal), Analysis (answer numeric questions using the in-game calculator), and Report (fill in a written summary, choose a chart type, populate the chart). The Cases part is a sprint of six independent mini-problems with their own exhibits.
The arithmetic is familiar: percentages, ratios, growth rates, weighted averages, and probability. The harder work is reading exhibits accurately, choosing the right denominator, picking a chart type that fits the data, and staying sharp through six fresh mini-cases when your attention is already worn down. Clean exhibit reading and disciplined pacing matter more than advanced math.
If you want to use a free tool to get a feel for the calculation rhythm, the free Redrock practice template is a low-friction first rep.
For the detailed workflow and a worked Southshore wolves example, read our in-depth Redrock guide.
Sea Wolf (30 minutes)
Sea Wolf is the optimization task inside Solve. The premise is straightforward. You are given three contaminated ocean sites. For each site, you build one three-microbe treatment that fits a set of attribute ranges and trait conditions.
Sea Wolf runs through four steps per site: choose two profiling characteristics, categorize the ten available microbes (keep, save for the next site, or discard), build a prospect pool through four selection rounds, and pick the final three-microbe treatment. The whole game runs on one 30-minute timer covering all three sites, so a practical rhythm is roughly eight to ten minutes per site.
The task is simple to describe and harder to execute well under time pressure. You are juggling three numerical attributes, a desired trait, an undesired trait, and a 20% effectiveness penalty for each missed condition. The arithmetic is light, but you have to do it across many candidate combinations while keeping an eye on the next site's preview information and the trade-offs you have already locked in. Targets near the edge of an allowed range are where penalties often creep in.
For a low-commitment first rep on the optimization rhythm, the free Sea Wolf practice simulation is a useful warm-up.
For the penalty model and a worked Density / Energy / Size example, read our in-depth Sea Wolf guide.
Sustainable Futures Lab (20 minutes)
The Sustainable Futures Lab is the third Solve game and the most recent addition to the mix. It is text-heavy and unlike the other two. Instead of working through numbers or optimizing across constraints, you join a small sustainability team and make a connected sequence of judgment calls about how to handle a developing problem.
The structure is a ranking task followed by twelve single-choice questions, all anchored to one evolving scenario. The setting changes between runs (reefs, watersheds, urban heat, and others have been reported), but the shape stays stable: dense scenario paragraphs, two to four answer options per question, and a consequence screen after each choice. The whole thing runs on a 20-minute timer.
Sustainable Futures Lab appears on 85-minute Solve invitations, not 65-minute ones. Regional rollout is still expanding. As of April 2026, candidate reports place it in Germany, the Middle East, Southeast Asia, the United States, and Canada. McKinsey has not confirmed a global rollout date, so the simplest check remains the invitation email itself.
The challenge here is reading the situation accurately, sequencing the work, and staying consistent when several answers sound equally plausible. Domain knowledge plays a small role; the bigger skill is judgment under pressure. For practice, it helps to watch for eight recurring decision traits, including prioritization, action under uncertainty, stakeholder compromise, and adaptability.
For a low-friction first rep on the judgment rhythm, the free Sustainable Futures Lab simulation is a quick way to feel out the format under realistic time pressure.
For the full structure, eight-trait lens, and Island Reef Recovery walkthrough, read our in-depth Sustainable Futures Lab guide.
What the McKinsey Solve assessment really tests
Older guides often describe Solve as a test of "five cognitive dimensions": critical thinking, decision making, meta-cognition, situational awareness, and systems thinking. That terminology dates back to early Imbellus marketing copy and only loosely maps to the current games.
A more useful reading is to think about Solve as three distinct demands, one per current game.
- Redrock tests quantitative reasoning under structure. Can you read exhibits accurately, run percentage and ratio calculations cleanly, choose a chart that fits the data, and stay sharp through six unrelated cases at the end?
- Sea Wolf tests constrained optimization. Can you compare options against multiple attribute ranges and trait rules, count penalties accurately, and pick the trio that minimizes total misses?
- Sustainable Futures Lab tests judgment under uncertainty. Can you read pressure, sequence the work, and keep a small team moving when several answers sound reasonable?
The common thread across all three is reasoning under time pressure with incomplete information. The scenarios supply the domain context you need, which means a strong analytical background can take you most of the way, regardless of consulting experience.
How scoring works (and what McKinsey does not publish)
McKinsey does not publish a Solve scoring rubric. There is no public pass mark, no released formula, and no official breakdown of how the games are weighted. Several pages on the open web claim to have a "secret formula" or an exact score threshold. Treat those claims with skepticism.
The clearest public anchor is McKinsey's own communication. The official Solve FAQ states that performance on the assessment is reviewed alongside the rest of your application. For prep, assume both the choices you submit and the path you take through the task matter. Each game has its own timer, so finishing cleanly with a small buffer is generally better than timing out mid-question.
Solve is one input into the screening decision. A weaker Solve run is reviewed in the context of your CV, cover letter, and interview signal. A strong Solve run reinforces a strong application, but it does not secure an offer by itself.
For a deeper score discussion, including process versus outcome signals and how to think about a weaker run, see the article on what a good McKinsey Solve score looks like.
Legacy games: Ecosystem, Ocean Cleanup, and Plant Defense
Three older Solve games still come up in forums and older blog posts, but none are in current standard 2026 invitations. Here is the quick version so you do not waste prep time on the wrong game.
- Ecosystem Building Game. Historically one of the longest-running Solve games, where candidates assembled a balanced ecosystem from a species list. It was heavily phased out during 2025 and is rare in current 2026 invitations, though it may still appear in non-standard cases. If your invitation lists an unusual length, or if you want broader coverage after practicing the current games, a few timed Ecosystem reps can still be useful.
- Ocean Cleanup. The predecessor to Sea Wolf, sometimes called "ocean treatment" in older candidate forums. The scenario name changed during the rollout, but the optimization-style reasoning carried over into the current Sea Wolf game.
- Plant Defense. An earlier Solve game where candidates defended a native plant species from invasive threats. It was replaced by Redrock as the data-heavy partner to Sea Wolf and is not in current invitations.
If your search led you here through one of those legacy names, the safest signal is your invitation email. Anything outside Redrock, Sea Wolf, and (on 85-minute invites) Sustainable Futures Lab is unlikely in current 2026 cycles. For a side-by-side inventory of all the games McKinsey has used over the years, the McKinsey PSG mini-games overview is the support page that owns that comparison.
How to prepare for McKinsey Solve
Prep for Solve is mostly about timed reps. The format repeats, but the details change. That makes practice runs more useful than memorizing answer keys.
- A few days before the test. Focus on full timed runs of each game on your invitation. Skip deep theory. The biggest risk in a short window is finding out what a 35-minute Redrock or a 30-minute Sea Wolf actually feels like for the first time on test day.
- One to two weeks out. Build a structured rotation: one full run per game, plus a focused drill on whichever game felt weakest. Add a short session on chart selection and percentage fluency for Redrock, and on edge-range thinking for Sea Wolf.
- Two or more weeks out. Use the early time to learn the formats, then shift to timed reps with light theory work in parallel. Two or three full runs per game across the prep window is usually enough.
For the full multi-week prep plan, including the order to practice the games, common pacing patterns, and how to handle a weaker run mid-prep, read our full prep plan for McKinsey Solve.
Common McKinsey Solve myths
Solve attracts a steady stream of misconceptions. The four below are the ones that most often distort prep plans.
- "Solve is just a video game." The visual style is gamified, but the underlying assessment is structured. Each game runs on a fixed timer, and your decisions, trade-offs, and pressure management can matter for the assessment. Treat it like a test, not a casual play session.
- "You can memorize answers." Microbe names, study subjects, attribute values, and scenario details rotate between runs. The structure of each game is what stays consistent, so practice the structure rather than specific answer keys.
- "Imbellus is a different test." Imbellus is the legacy name. The company built the original platform, McKinsey kept it, and the brand was retired in favor of "Solve." If a forum thread or older blog post calls it the "McKinsey Imbellus test," they are talking about the same assessment you are about to take.
- "Sustainable Futures Lab is universal in 2026." Sustainable Futures Lab is currently reported on 85-minute Solve invitations only, and the regions where candidates see it are still expanding. If your invitation says 65 minutes, you will not see Sustainable Futures Lab.
Which guide should you read next?
Choose the next guide based on what you need.
| If you are... | Read next |
|---|---|
| Just learning what Solve is and want the broad picture | Stay on this article and skim the comparison matrix |
| Preparing for the 65-minute Solve | The in-depth Redrock guide and in-depth Sea Wolf guide |
| Preparing for the 85-minute Solve | The Redrock and Sea Wolf guides above, plus the in-depth Sustainable Futures Lab guide |
| Worried about your score or what counts as a good run | The McKinsey Solve score article |
| Building a multi-week prep plan | The McKinsey Solve prep-plan article |
| Searching for an older game name (Imbellus, Ecosystem, Ocean Cleanup) | The Imbellus, Ecosystem, or Ocean Cleanup article |
| Looking for a side-by-side game inventory | The McKinsey PSG mini-games overview |
Frequently asked questions
Is McKinsey Solve the same as the PSG? Yes. PSG is short for Problem Solving Game. McKinsey Solve, the PSG, the Digital Assessment, and the older Imbellus name all refer to the same assessment.
Is Imbellus the same as McKinsey Solve? Yes. Imbellus is the company that built the original platform. McKinsey kept the platform and rebranded the test as Solve. Older articles and forum threads that mention "McKinsey Imbellus" are describing the current Solve assessment.
How long is McKinsey Solve in 2026? In current 2026 cycles, the standard invitation is 65 minutes (Redrock and Sea Wolf) or 85 minutes (Redrock, Sea Wolf, and Sustainable Futures Lab). The exact length is in your invitation email.
Will I get the Sustainable Futures Lab? If your invitation says 85 minutes, yes. If it says 65 minutes, no. Sustainable Futures Lab is reported on 85-minute invitations only, and the regions where it appears are still expanding. The invitation email is the cleanest signal.
Is Ecosystem Building still in McKinsey Solve? No, not in current standard 2026 invitations. Ecosystem was heavily phased out during 2025. If you are reading older guides that center on Ecosystem, treat that material as legacy.
How is McKinsey Solve scored? McKinsey does not publish a public scoring rubric. The official Solve FAQ states that performance is reviewed alongside the rest of your application, and that the assessment captures decisions across a run. There is no released pass-or-fail threshold. The article on what a good McKinsey Solve score looks like goes deeper on what is actually known and what is speculation.
How should I prepare if my test is in a few days? Skip theory and run full timed reps of each game on your invitation. The biggest risk in a short window is meeting a 35-minute Redrock or a 30-minute Sea Wolf for the first time on test day. Two or three full runs per game across the days you have is usually a strong use of the time.
What to do next
If you are preparing for the full Solve mix, the all-in-one McKinsey Solve bundle covers Redrock, Sea Wolf, and Sustainable Futures Lab in one place. If you would rather compare options first, the McKinsey Solve collection lists the products tied to the assessment, including bundles, simulations, solvers, and free templates.
