Author: Taylor Warfield, Former Bain Manager and interviewer

Last Updated: March 19, 2026

The McKinsey Solve is an online assessment that screens candidates before case interviews. As of mid-2025, it consists of two games (Redrock Study and Sea Wolf) and takes about 65 minutes. Roughly 80% of candidates who take the Solve are eliminated, making it one of the toughest filters in consulting recruiting.

 

This guide covers everything you need to know: how each game works, how McKinsey scores you (including the process score most candidates miss), and the specific strategies that help candidates pass. Having coached hundreds of candidates through this assessment, I will walk you through exactly what to expect.

 

But first, a quick heads up:

 

McKinsey, BCG, Bain, and other top firms accept less than 1% of applicants every year. If you want to triple your chances of landing interviews and 8x your chances of passing them, watch my free 40-minute training.

 

What Changed in 2026?

 

McKinsey made a significant change to the Solve in mid-2025: the Ecosystem Building game was phased out globally. Most candidates now receive only two games instead of three.

 

Here is what is different compared to older versions of the test:

 

• Two games instead of three. The current Solve consists of Redrock Study and Sea Wolf. Total active game time is approximately 65 minutes.

 

• Ecosystem Building is retired. If your invite email specifies 110 minutes, you may still receive Ecosystem as a third game. However, the vast majority of candidates in 2026 do not encounter it.

 

• Sea Wolf is now standard. Previously in beta testing, Sea Wolf (also called Ocean Cleanup) is now a core part of every candidate's assessment.

 

If you are reading guides that still describe three games at 110 minutes, that information is outdated. This guide reflects the current format as of March 2026.

 

What Is the McKinsey Solve?

 

The McKinsey Solve is a gamified assessment that evaluates how you think, not what you know. You play through ecology-themed scenarios that test your problem-solving abilities. No business knowledge is required and you do not need any gaming experience.

 

McKinsey uses this test to screen thousands of applicants efficiently. It replaced the old McKinsey Problem Solving Test (PST) starting in 2019 because it provides richer data on how candidates actually approach problems.

 

The test currently consists of two games:

 

• Redrock Case Study: Analyze data about wildlife populations, perform calculations, complete a business-style report, and answer independent mini-case questions.

 

• Sea Wolf (Ocean Cleanup): Select microbes to treat polluted ocean sites based on their biological characteristics and attribute values.

 

You take the test at home on your own computer. According to McKinsey's official guidelines, you should complete the test alone without assistance from others, applications, websites, AI tools, or pre-prepared notes. You are free to use pen, paper, and a calculator.

 

A critical point most candidates miss: the Solve does not just score your final answers. It tracks every click, every scroll, and every decision you make. Your problem-solving process matters just as much as getting the right answer.

 

Is the Solve the Same as the PSG, Imbellus Game, or Digital Assessment?

 

Yes. All these names refer to the same test. You will see them used interchangeably across forums, older McKinsey materials, and other websites.

 

• McKinsey Solve is the current official name.

 

• Problem Solving Game (PSG) was the name used from roughly 2020 to 2022.

 

• McKinsey Digital Assessment is another term McKinsey has used in the past.

 

• Imbellus Game/Test is named after Imbellus, the company that developed the original version (later acquired by Roblox in 2021).

 

Where Does the Solve Fit in McKinsey's Interview Process?

 

The McKinsey interview process follows a predictable sequence. Understanding where the Solve fits helps you plan your preparation.

 

• Step 1: Submit your application. This typically includes your resume, cover letter, academic transcripts, and any referrals.

• Step 2: Initial resume screen. McKinsey does a quick review to filter out incomplete applications. Most candidates who meet basic qualifications advance to the Solve.

• Step 3: Take the McKinsey Solve. You receive an email invitation with instructions and a deadline. Most candidates get one to two weeks to complete the test. Plan to be ready within one week of submitting your application.

• Step 4: Detailed application review. McKinsey reviews your Solve results alongside your resume and other materials. According to candidate reports, only about 20 to 30% of candidates who take the Solve advance to interviews.

• Step 5: First round interviews. Typically two interviews, each 40 to 60 minutes, including a case interview and behavioral questions.

• Step 6: Final round interviews. Two to three interviews with more senior consultants or partners. The cases may be less structured and more discussion-based.

• Step 7: Offer decision. You typically hear back within a few days to a week after final rounds.

 

Who Takes the McKinsey Solve?

 

Nearly everyone applying to McKinsey for a consulting role takes the McKinsey Solve. According to Glassdoor data from 2025, this includes undergraduate students applying for Business Analyst positions, MBA students applying for Associate positions, PhD/JD/MD candidates, and experienced hires from industry.

 

The only candidates who might skip it are very senior hires (Partner-level), candidates with exceptionally strong referrals, or candidates in offices piloting different processes. Even these exceptions are office-dependent. The safest assumption is that you will take the Solve.

 

Does the Test Differ by Role or Region?

 

No. The McKinsey Solve is standardized regardless of which office you are applying to, what position level you are targeting, or your educational background. A Business Analyst candidate in Chicago takes the same test as an Associate candidate in London. This standardization is intentional. McKinsey wants to evaluate everyone on the same playing field.

 

How Is the McKinsey Solve Scored?

 

Unlike a traditional test, you are not just scored on whether you got the right answer. McKinsey evaluates both what you produce and how you produce it. This dual scoring system is what makes the Solve different from any assessment you have taken before.

 

What Is the Product Score?

 

The product score measures the quality of your final outputs. In Redrock, this means whether your calculations are correct, your report is accurate, and your mini-case answers are right. In Sea Wolf, it means whether your selected microbes meet the site requirements, whether attribute averages fall within target ranges, and whether you included the desirable trait and excluded the undesirable trait.

 

What Is the Process Score?

 

The process score is what makes the Solve unique. The assessment tracks everything you do: every mouse click, every scroll, how long you spend on each section, when you change your mind, and what order you consider information in.

 

McKinsey uses this behavioral data to evaluate whether you approach problems systematically rather than randomly, navigate the interface efficiently, commit to choices rather than constantly backtracking, use the provided tools (calculator, journal) appropriately, and pace yourself well.

 

How Do the Scores Combine?

 

Your final score combines both product and process components. McKinsey does not publish the exact weighting, but both matter significantly. You can get a mediocre score even with correct answers if your process was messy. And you can get a decent score with a few wrong answers if your process was exemplary.

 

Think about it from McKinsey's perspective. They want consultants who solve problems efficiently and systematically, not people who stumble into correct answers through trial and error.

 

What Score Do You Need to Pass?

 

McKinsey does not publish passing scores or cutoffs. Based on candidate reports, scores are compared to high performers at McKinsey. The closer your pattern matches successful consultants, the better you score. Office competitiveness and recruiting cycle volume also affect the effective threshold.

 

You can request your score from McKinsey after completing the assessment. They will tell you your percentile range (which quartile you fall into). However, they will not tell you whether you passed or how close you were to the threshold. You will only know for sure when you receive an interview invitation or a rejection.

 

What Skills Does the McKinsey Solve Test?

 

McKinsey designed the Solve to assess five cognitive abilities. Understanding these helps you approach the games with the right mindset.

 

Skill	What McKinsey Is Looking For
Critical Thinking	Making judgments based on objective analysis. Identifying relevant data vs. noise. Drawing logical conclusions from evidence.
Decision Making	Choosing the best course of action under time pressure or with incomplete information. Committing to decisions rather than endlessly deliberating.
Metacognition	Deploying appropriate strategies to make problem-solving easier. Having a clear approach before executing. Using tools effectively.
Situational Awareness	Interpreting and predicting an environment. Considering second and third-order effects. Maintaining big-picture awareness.
Systems Thinking	Understanding complex causal relationships between elements. Recognizing feedback loops and interdependencies.

 

Research on the Imbellus assessment methodology suggests that Decision Making and Metacognition are the key differentiators. Most candidates can demonstrate some critical thinking and systems thinking. But making deliberate, efficient decisions under pressure and using structured strategies to simplify complex problems is what separates top scorers from everyone else.

 

Game 1: Redrock Case Study (Complete Guide)

 

Redrock is the most business-like game in the Solve. It resembles a traditional consulting assessment with data analysis, calculations, and report writing. This game has the tightest time pressure, and many candidates struggle to finish everything in the allotted time (approximately 35 minutes).

 

What Is the Redrock Scenario?

 

You are working on the Island of Redrock, a nature preserve with various wildlife populations. The most common scenario involves wolf and elk populations across different geographic areas. Your job is to analyze population data, perform calculations, and complete a report with your findings.

 

Redrock has two distinct parts that you must complete within the time limit. Part 1 is the Study, which has three phases: Investigation, Analysis, and Report. Part 2 is the Mini Cases, which consists of six independent questions you answer sequentially.

 

How Does the Investigation Phase Work?

 

During Investigation, you see a case description with background information, charts, graphs, and tables. Your job is to identify the key data points you will need for calculations and drag them into your Research Journal.

 

Only about 10 to 15% of the data shown is actually needed. Grabbing everything wastes time and clutters your workspace. In my experience coaching candidates, the best approach is to read the case objective first, then skim for calculation instructions (which tell you what math you will need and what numbers to collect), and then collect data systematically.

 

Edit the auto-generated labels on your journal cards as you go. Clear labels save significant time in the Analysis phase. Budget 8 to 10 minutes maximum for Investigation.

 

How Does the Analysis Phase Work?

 

Analysis presents three quantitative questions with sub-parts. You use an on-screen calculator and your Research Journal to perform the calculations and input your answers.

 

A crucial detail: McKinsey logs all your calculator activity. This directly affects your process score. Do ALL calculations on the provided calculator, even simple ones you could do mentally. If the Solve sees you entering a correct answer without having used the calculator, it may flag your process as unclear.

 

The types of calculations you will encounter include basic arithmetic (adding populations, multiplying by percentages), percentage calculations, simple and compound growth rates, weighted averages, and conversions between percentage points and percentages.

 

Watch out for this common trap: "Increase by 5 percentage points" means adding 5 to the percentage (10% becomes 15%). "Increase by 5%" means multiplying (10% becomes 10.5%). Getting this wrong is one of the most frequent errors in Redrock.

 

Save your answers to the journal. You will need them for the Report phase. Budget 10 to 12 minutes for Analysis.

 

How Does the Report Phase Work?

 

The Report phase gives you a pre-written report with blanks to fill in. You insert numerical values from your calculations, add comparison words (higher, lower, equal to), and create a chart.

 

For the chart, you will typically choose between a bar chart (best for comparing quantities across categories), a line chart (best for showing change over time), or a pie chart (best for showing parts of a whole). Pick the chart type that best communicates the insight from your data.

 

Budget 5 to 7 minutes for the Report phase.

 

What Are the Mini Cases?

 

After the Study, you face six independent questions. These are thematically related to Redrock but do not use data from the Study. You answer them sequentially and cannot skip ahead.

 

The question types include calculation questions (weighted averages, probabilities), formula identification, verbal reasoning (true/false based on given text), data interpretation (finding medians, modes, and means from charts), and visualization questions (choosing the best chart type for a dataset).

 

Budget at least 8 to 10 minutes for this section. Do not let the earlier phases consume all your time. The Mini Cases are worth significant points and many candidates lose marks simply because they rushed through them.

 

How Should You Manage Time in Redrock?

 

Redrock is the most time-pressured game. Here is a recommended breakdown based on a 35-minute time limit:

 

Phase	Time	Cumulative
Investigation	8-10 min	8-10 min
Analysis	10-12 min	18-22 min
Report	5-7 min	23-29 min
Mini Cases	6-12 min	35 min

 

If you are running behind, streamline Investigation (collect only essentials), move faster through Analysis (but stay accurate), and keep the Report concise. Never sacrifice the Mini Cases.

 

Game 2: Sea Wolf / Ocean Cleanup (Complete Guide)

 

Sea Wolf is the newer game, fully integrated as a standard part of the Solve since late 2024. You select microbes to treat polluted ocean sites based on their biological characteristics. This game combines pattern matching with optimization.

 

What Are the Key Concepts in Sea Wolf?

 

Every site and microbe is defined by two types of characteristics. Attributes are three numerical values ranging from 1 to 10 (for example, permeability, mobility, energy). Traits are four binary (yes/no) characteristics (for example, light sensitivity, aerobic, heat resistance).

 

Each site specifies target ranges for three attributes (such as permeability 4 to 6), one desirable trait that must be present in at least one of your selected microbes, and one undesirable trait that must be absent from all selected microbes.

 

Your goal is to select three microbes for each site whose combined characteristics match the requirements. You will treat two to three sites in total.

 

How Is Each Site Scored?

 

Your treatment effectiveness for each site is scored out of 100%. Each criterion is worth 20%:

 

Criterion	Points	Requirement
Attribute 1 in range	20%	Average within target
Attribute 2 in range	20%	Average within target
Attribute 3 in range	20%	Average within target
Desirable trait present	20%	At least 1 microbe has it
Undesirable trait absent	20%	No microbe has it

 

A perfect score is not always achievable depending on the available microbes. Aim for the highest score possible given your options.

 

What Are the Four Steps of Sea Wolf?

 

Each site follows the same four-step process.

 

• Step 1: Define Selection Criteria. Choose two characteristics (attributes or traits) to filter the initial microbe pool. If you select an attribute, define a range of 2 (such as 4 to 6). If you select a trait, choose yes or no. Pick one attribute with an extreme target range (far from the midpoint of 5.5) and one trait (the desirable or undesirable one).

• Step 2: Assign or Reject Microbes. You see 10 microbes and information about two sites. For each microbe, decide whether to assign it to Site 1, Site 2, or reject it. Assign a microbe to a site if at least 2 of 3 attributes fall within the target ranges and it does NOT have the undesirable trait.

• Step 3: Build Your Prospect Pool. You start with 6 microbes and add 4 more by choosing one from each set of 3 options. For each choice, eliminate any with the undesirable trait first, then check for the desirable trait, then count how many attributes are in range.

• Step 4: Select Final 3 Microbes. From your 10-microbe pool, choose 3 that together create the best treatment. Attribute values are averaged across the 3 microbes, and the average must fall within the target range.

 

Math shortcut: Instead of dividing by 3 to find averages, multiply the target range by 3. If the target is 4 to 6, the acceptable sum of 3 microbes is 12 to 18. This is faster and eliminates division errors.

 

How Should You Manage Time in Sea Wolf?

 

You have approximately 30 minutes for all sites. If treating three sites, budget about 10 minutes per site. If treating two sites, you have about 15 minutes each. The process gets faster as you learn the interface, so expect the first site to take the longest.

 

The most common mistakes in Sea Wolf are including a microbe with the undesirable trait (which costs 20% immediately), forgetting to include the desirable trait, and calculating averages incorrectly. Double-check every selection before finalizing.

 

What About Ecosystem Building?

 

Ecosystem Building was a core game in the McKinsey Solve from 2017 through mid-2025. As of July 2025, it has been phased out globally. However, if your invite email specifies 110 minutes instead of 65 minutes, you may still encounter it as a third game.

 

In Ecosystem Building, you selected 8 species from a pool of 39 to create a self-sustaining food chain, then chose a location where all species could survive. The 39 species were organized into three groups of 13, each sharing terrain requirements. The key to solving it quickly was identifying which group to build from, starting with the producers, and tracing through the eating rules to confirm every species survived.

 

If you think you may encounter this game, prepare for it separately. But for the vast majority of candidates in 2026, Redrock and Sea Wolf are the only two games you need to focus on.

 

How Should You Prepare for the McKinsey Solve?

 

McKinsey says you do not need to prepare. In my experience, that is like saying you do not need to prepare for case interviews. Some people pass without preparation, but the pass rate is only about 20 to 25%. Why take the risk when a McKinsey career could be worth millions over the course of your career?

 

What Does Preparation Actually Do?

 

Preparation does several things that directly improve your score. It familiarizes you with the game mechanics so you do not waste test time figuring out how things work. It lets you develop and internalize strategies through practice. It builds speed and accuracy under time pressure. And it improves your process score because the more comfortable you are, the more organized and systematic your approach will be.

 

Preparation does NOT give you the exact questions (every Solve is unique), guarantee you will pass, or replace genuine cognitive skills. But most candidates have the underlying ability and just need to learn how to demonstrate it effectively under test conditions.

 

What Is the Best Preparation Process?

 

• Step 1: Understand the assessment (2 to 3 hours). Read this guide thoroughly. Know what each game involves, how scoring works, and what behaviors the test rewards.

• Step 2: Learn the strategies (2 to 3 hours). Study the specific approaches for each game. Create notes or flashcards for key rules. Understand not just what to do, but why.

• Step 3: Practice with simulations (5 to 15 hours). This is the most important step. Play through realistic practice scenarios multiple times. Each run helps you internalize strategies, build speed, and identify weak points. Several third-party platforms offer Solve simulations online.

• Step 4: Brush up on quantitative skills (2 to 5 hours). For Redrock, practice percentages, growth rates, weighted averages, and basic probability. GMAT Integrated Reasoning questions are useful practice. For Sea Wolf, practice logical deduction and working with numerical ranges.

 

The ideal preparation timeline is 2 to 4 weeks. But even a few days of focused practice is better than going in cold.

 

What Should You Expect on Test Day?

 

How Should You Set Up Before the Test?

 

Complete McKinsey's technical check at least 24 hours before the test. Ensure your computer meets the requirements (a fast machine with at least 8 GB of RAM) and that your internet connection is stable. The Solve uses 3D animation, so a slow computer or weak internet can cause serious performance issues.

 

Find a quiet space where you will not be interrupted. Have these items ready: pen and paper, a calculator, water, and a spare pen. Turn off notifications on all devices. Get good sleep the night before.

 

What Should You Do During the Test?

 

The tutorials before each game are untimed. Take your time with them. Take notes on key rules and mechanics. Make sure you understand the objective before the timer starts.

 

During the timed portions, think before you act (your process is being recorded), be systematic rather than random, use the provided tools (calculator, journal), and manage your time across all phases. If something does not work immediately, stay calm and adjust.

 

What Happens After You Take the Solve?

 

Most candidates hear back within one to two weeks. Timing varies based on recruiting cycle, office volume, and your school's timeline. If you have not heard back after two weeks, send a polite follow-up email to your recruiter.

 

If you pass, begin preparing for case interviews immediately. If you do not pass, most McKinsey offices allow reapplication after 6 to 12 months. Request your score to understand where you stand and use the waiting period to strengthen your profile.

 

How Does the McKinsey Solve Compare to BCG and Bain Assessments?

 

McKinsey is not the only consulting firm with a digital assessment. Here is how the Solve compares to the assessments used by BCG and Bain.

 

Feature	McKinsey Solve	BCG Pymetrics	BCG Casey	Bain SOVA
Duration	~65 min	~30 min	~30 min	~60 min
Format	Gamified simulations	Mini-games	Chatbot case	Traditional test
Business knowledge	No	No	Yes	Some
Right answers exist	Yes	Often no	Yes	Yes
Process score	Yes	Sort of	No	No
Preparability	Moderate	Low	High	High

 

If you are applying to multiple MBB firms, the preparation strategies differ significantly for each assessment. The Solve requires the most unique preparation because of its gamified format and process scoring. For more on what to expect at each firm, see our guides to the consulting interview process.

 

Frequently Asked Questions

 

How Long Is the McKinsey Solve?

 

The current McKinsey Solve takes approximately 65 minutes of active game time for two games (Redrock Study and Sea Wolf). Tutorials before each game are untimed and do not count toward this total. If your invitation email specifies 110 minutes, you may receive a third game (Ecosystem Building), but this is increasingly rare in 2026.

 

What Equipment Do I Need for the McKinsey Solve?

 

You need a PC or Mac with at least 8 GB of RAM, a stable internet connection, and an updated browser. Tablets and phones are not supported. A mouse is optional but recommended for faster navigation. You should also have pen, paper, and a calculator ready.

 

Can I Use a Calculator During the McKinsey Solve?

 

Yes. Redrock includes a built-in on-screen calculator, and you should use it for all calculations (McKinsey logs your calculator activity as part of your process score). You can also have a physical calculator on your desk.

 

What Is the Pass Rate for the McKinsey Solve?

 

The estimated pass rate is around 20 to 30%, meaning roughly 70 to 80% of candidates are eliminated at this stage. This makes the Solve one of the most selective filters in consulting recruiting. The rate can be even lower at competitive offices like New York and London.

 

Can I Retake the McKinsey Solve If I Fail?

 

Not immediately. You will need to wait for a new recruiting cycle, which is typically 6 to 12 months depending on the office and your school's policies. Some candidates report waiting up to two years. Check with your recruiter for specific guidance.

 

Does McKinsey Monitor Me Through My Webcam?

 

No. McKinsey does not use webcam monitoring during the Solve. However, they do expect you to complete the test alone without assistance from other people, applications, websites, or AI tools. Using such assistance could result in disqualification or a rescinded offer.

 

Should I Prepare Even Though McKinsey Says I Do Not Need To?

 

Absolutely. While McKinsey officially states that no specific preparation is needed, candidates who understand the games and practice beforehand consistently perform better. The unfamiliar format, time pressure, and process scoring all favor candidates who have seen the games before. Even a few hours of preparation can make a meaningful difference.

 

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