Replacing paper-based PST examination, McKinsey is deploying the game-based assessment that leverages artificial intelligence and algorithms to score candidates. McKinsey argues that the game, unavailable anywhere else online, strips biases and inherent advantages from the testing process. Candidates are no longer able to practice in advance as they did with the PST. Regardless of their backgrounds, candidates are now equal.

1. What is McKinsey Problem-Solving Game?

The McKinsey Problem-Solving Game, also called McKinsey Digital Assessment or Imbellus Game, is a gamified assessment developed by the Imbellus company. The digital assessment translates the real world of consulting into a set of games that allow McKinsey to score how candidates think and approach problems. According to McKinsey, there is no preparation and business background needed for the game.

After passing the resume screening round, McKinsey will send you the information with a link you need to get started. The process is now more flexible, allowing you to take the test either from home or at the test center set up by McKinsey. You can choose to take the assessment on your laptop, PC, or Mac. Once you are in the system, a technical check will inform whether your devices meet specific requirements. Then you will be given instructions about the assessment, including a video tutorial before entering each game.

1.1 Problem-Solving Game is now applicable to all positions McKinsey recruits

The PSGs are now applicable to all applicants applying for McKinsey. McKinsey has been rolling out the games to about 80% offices around the world. The rest will use the game in the next 1 to 2 years. In the past, some offices did not require candidates to join the test round if they have a good GMAT score and an MBA. But these are not advantages since the games are introduced. All applicants are now equal to one another.  

1.2 There are no right or wrong answers for the Problem-Solving Game

McKinsey is looking at how you approach problems by playing a series of 2 out of 5 games, which will be customized to each candidate. In other words, they evaluate how you reach the solution rather than getting the right answer. The choice you make and the path you take in playing games will be collated to inform recruiters whether you are the best fit and most likely to succeed in consulting. 

1.3. No business knowledge is tested nor will you require any experience in video gaming

Candidates will not be tested on business knowledge. Prior experience in video gaming, according to McKinsey’s talent acquisition team, is unnecessary either. In other words, any inherent advantages such as business and industry background will be removed. 

They want to create equality between candidates no matter what their background is. In fact, while no testing on business is true, getting familiar with playing video games in a gamified environment might definitely give you an edge over candidates without practicing beforehand. 

So does it contradict what McKinsey mentions? 

No, we will get to this point and you will find out later in this article. 

2. McKinsey Problem-Solving Game Format: How It Works?

2.1 It is a timed 60-minute assessment

The time limit hovers around 60 – 80 minutes. Candidates sit the two games officially for 60 minutes, and the rest of 15 – 20 minutes is for tutorials and instructions. The time for each game varies from candidate to candidate, with around 35 – 40 minutes for the first game and 20 – 25 minutes for the second game.

All games in the digital assessment are brain teasers, which means candidates have to brainstorm exhaustively. As a result, 60 minutes can cause you to be somewhat wiped out. So the best advice, though sounding cliché, is to keep yourself relaxed and have a little snack by your side to remain energetic throughout the games.  

The game can be taken on a candidate’s personal computer and anywhere they stay most focused and productive. 

For tutorials, you can either skip this part or leverage this time to make preparations such as getting an overview and drawing up possible strategies for the games you will play. 

Candidates CANNOT pause the games once entering the system.

2.2 Candidates will play 2 out of 5 games

McKinsey confirms that five games will be used for the assessments, including Ecosystem Building, Plant Defense, Disease Management, Disaster Management, and Migration Management. Ecosystem Building is the first game with two versions designed either in aquatic or terrestrial environments. The other four are used interchangeably for the second game. 

In terms of the first challenge, candidates are placed into either a mountain ridge or a coral reef randomly. The overarching goal is to design a sustainable ecosystem with a chain of animals. 

The second game, Plant Defense Game, largely resembles a tower-defense game where you place defensive objects to prevent invaders from approaching your base. 

Nevertheless, the Plant Defense Game is just what most candidates will encounter in regard to the second game. A small percentage of candidates can take one of the “less frequent” following games as follows:

  • Disaster Management involves identifying the nature of natural disasters such as hurricanes or wildfires and relocating the animals to the best area possible to minimize or to prevent the devastation caused by the disasters. 
  • Disease Management requires candidates to identify the infectious disease and the patterns of the disease, and given disease factors, to figure out what animals can be impacted.
  • Migration Management involves migrating a group of animals to another destination on the best route out of many other “best routes” while sustaining the most amount of resources and animals.   

While Disaster Management and Disease Management are becoming extremely rare (few reports are collected and according to people familiar with the games, they are still beta versions without any official results being produced), Migration Management appears to be the second most frequent game besides Plant Defense. It means that you are much more likely to encounter Migration Management than the other two.

2.3 Candidates are evaluated on five main skills

Candidates will be assessed based on five main skills including critical thinking, decision-making, meta-recognition, situational awareness, and adaptability. Excelling at these five qualities foreshadows a great consultant a candidate might become. 

Skills Descriptions
Critical thinking How a candidate synthesizes a set of facts to deliver a rational judgment
Decision-making How a candidate selects the best possible decision despite limitations among a number of options.
Meta-cognition How a candidate navigates to quickly learn and adapt to changing environments in search of solutions to problems more easily (e.g. testing hypotheses and taking notes).
Situational awareness How a candidate predicts the likely outcomes and draws up a corresponding strategic approach given a variety of variable factors
Adaptability How a candidate gets through the complexity of the system to play the games without getting overwhelmed, panicked, and baffled since a small change they make can impact the system as a whole.


The technology will only manage to focus on non-verbal cues. Results interpreted from the games essentially only assess candidates to a certain extent. A more complete version of consulting portraits is reflected best in case interviews.

It is difficult to tell what dimensions have the most weight. Those all five are minimal fundamental skills a consultant must possess.

3. Mini-Game 1: Ecosystem Building

3.1 What is your task?

Your task is to build a sustainable habitat for 8 species across the list of 40 species. Randomly, you might fall into one of two environments: a coral reef or a mountain ridge. 

Following are what is worth noting before delving into the game: 

  • Create a food chain of 8 species with predators and preys, you have the right to choose and change the animals until they fit the food chain. According to feedback from real test takers, it is impossible to form a perfect food chain, meaning that the chain you form might carry unsolved conflicts. So you don’t need to worry too much. The more animals survive, the better. 
  • Summarize a plethora of information. You might be astounded by the information offered by the game, with most of them being unusable and redundant. So practicing in advance might give you a chance to think of strategies to practice taking notes and summing up such a huge load of information.  
  • Make the food chain not only continuous but also compatible with the terrain so animals can survive with one another and complete their own missions. 

3.2 An overview of the two habitats you are tasked to resolve

Here’s are commons and differences between the two locations:

 Mountain RidgeCoral Reef
SpecificationsEach coordinate on the “Mountain Ridge” map has the 8 following specifications: Elevation, Temperature, Wind Speed, Humidity, Cloud Height, Soil pH, Precipitation, Air Pressure.Each coordinate on the “Coral Reef” map has the 7 following specifications: Depth, Water Current, Water Clarity, Temperature, Salt Content, Dissolved Oxygen, Wind Speed.
Food chain explanation
  • Most animals have a few predators (except for animals on the highest of the food chain), and prey. A series of predators and prey form a food chain surviving together on the map. For example, a wild boar is the food source of a tiger but hunts smaller species such as a mouse to survive. So we have the food chain: a mouse -> a wild boar -> a tiger. This is what you are tasked to solve.
  • Animals are categorized into producers (which yield calories without consuming calories) and consumers (which consume calories to live).
  • Consumers are grouped into herbivores (plant-eating animals), carnivores (animal-eating animals) and omnivores (eating both plants and animals), while producers absorb natural energies such as sunlight to produce calories.
  • An animal only survives if the location fulfills its required terrain specifications, otherwise, it will die out. The requirements are presented in a range, for example, Depth: 0 – 30 m.
  • A species lives if the calories intake is greater than the required calories. For example, a wild boar needs a minimum of 500 cal, and a mouse can offer 600 cal, so the wild boar can live by eating the mouse.
  • Nonetheless, it will be only easy until there are a variety of species. In the simulation, it’s not a standalone factor, you had to consider an array of factors, such as temperature, depth, and location for all the species, rather than one. Complexity “exponentializes” thereby.


McKinsey Problem Solving Game 1

  Figure 1: Mountain Ridge

McKinsey Problem Solving Game 2

  Figure 2: Coral Reef

3.3 Step-by-step guide to playing the Ecosystem Building Game

Each animal has its own specifications, this part only concerns the “CALORIES NEEDED” and “CALORIES PROVIDED” of each one. 

  • Calories needed: a level of calories a creature requires to survive.
  • Calories provided: a level of calories that a creature can provide to another creature if consumed. 

Here come the eating rules:

  • The creature (called A1 for the sake of simplicity) with the higher calories provided eats first. 
  • A1 will consume its prey, and it picks the prey with the highest calories provided (No consumption happens if A1 is a producer)
  • If there are two top prey creatures having the same calories provided, A1 will eat 1/2 of calories needed from each prey creature.
  • A1 will then eat the prey with the second-highest calories provided if the calories needed starts to reduce. The prey which has been consumed by A1 will become extinct and out of the food chain permanently. In this situation, your food chain loses one animal. 
  • The cycles are the same with the next creature below the A1 in the food chain. 
  • At the end of the process, all species in the food chain have new calories provided and calories needed. A species survives if its calories needed is equal to 0 and its calories provided is higher than 0. 

Now that you’ve learned about the eating rule, here is the recommended step-by-step guide to playing the game:

4. Mini-Game 2: Plant-Defense

4.1 What is your task?

In the second game, you act as a plant protector from invader species trying to threaten a specific area of land (one square on the map – usually the brightest one). Your task is to arrange a set number of obstacles and predators to prevent those creatures from destroying the specific land. 

You have to make judgments based on limited information to protect the particular land as long as possible. To do this, you’ll need to make a prediction of when and how the invaders would attack to protect the land. 

McKinsey says that the work of consultants can change a lot and you are expected to adjust quickly and understand a client’s problem given limited background resources and information. The game is launched to measure this skill. 

McKinsey Problem Solving Game 3

Figure 3: Plant Defense game

4.2 What do you need to know about the game?

  • Resources you are provided with can be categorized into two groups: defenders (coyote, snake, falcon, etc) and terrains (cliff, forest, rock, etc), The defenders are predators killing the invasive creatures while the terrains slow down or block these species. Note that one kind of defender only kills a certain number of invaders. The number of invaders always is greater than that of defenders.
  • You can place a total of 5 defenders and predators at the beginning. But all of these five will become inactivated/locked after each turn – which means you cannot change or remove its placement (the rest still remain activated). The cliff is the only exception, activating right after being placed.
  • Each defender is effective within a certain range (squares around the defender) – meaning that it can devastate the invaders once they enter the range. The size of the range varies depending on each type of defender. It can be interpreted that the more powerful the defender is, the smaller the range is.
  • Unlike the defender, each terrain is effective differently towards types of invaders. Specifically, while the mountain can block the invader, the forest only slows them down.
  • Each defender and terrain occupies one square. You can’t put a defender on another existing defender, but you can replace the existing terrain by placing another terrain on it.
  • But defender and terrain can exist in tandem on one square, increasing the effectiveness of the two.
  • Invaders appear in a population of 100 – 200 animals each moving to the specific land you’ll have to defend. The number of invaders increases as you proceed.
  • Invaders follow the possible path (a yellow arrow) to move closer to the particular land. They only change direction if blocked by terrain.


4.3 How to beat the Plant Defense?

The objective of the game is to protect the particular land as long as possible, of course, the most optimally. Since it quite resembles a tower-defense game, tactics used in the Tower-defense game are essentially applicable to the Plant Defense game of McKinsey.  

You won’t be able to change the objects once placed after a number of turns, and invaders appear from all directions so just paying attention to the appearance of invaders can’t help you that much in protecting your base land. Instead, plan for future invaders and predict, though hardly 100% precisely, where they could come from.

Strategy #1: Place as many layers as possible 

Since invaders can come from anywhere from the border of the map, creating a round defense is necessary. You’ll need 8 resources to protect the particular land right away. 8 resources correspond to 8 cells around the land. Let’s see the picture below for clarity. 

Figure 4: Plant Defense game

With this tactic, the most powerful resources will be prioritized to be put closest to the land, while the less powerful but wider-range ones cover the outer rings. 

Strategy #2: Have a big picture mindset

Don’t just focus on specific starting points of invaders, they can come out from anywhere and at any time. You are expected to anticipate their appearance, possible trajectories, and arrange your limited resources with the only aim of keeping the particular land alive as long as possible. 

There will be several types of invaders. Getting accustomed to them might take a few turns to test out what types of resources work best for different types of invaders. 

5. Mini-Game 3: Disaster Management

Disaster Management, for the sake of simplicity, requires candidates to identify the natural disasters in an ecosystem and to relocate the animals to another area aimed at maximizing survivability (or minimizing the devastation caused by disasters).

This mini-game is an alternative to a plant defense game. Unlike the plant defense game, you will be allowed to play it once because it doesn’t include multiple maps. 

6. Mini-Game 4: Disease Management

In the Disease Management game, you are tasked to identify the disease and make a prediction of what animals can be impacted. Given disease characteristics, select a treatment to optimize for the animal’s survival.

The goal is explanatory. But it’s not as easy as it seems. You have to deal with a large volume of information and then bring out a treatment plan. Consultants are expected to work out a large volume of information quickly and precisely to mitigate the most risks. And this simulation mimics that setting.

7. Mini-Game 5: Migration Management

The Migration Management game requires candidates to migrate a group of 50 animals to another destination. What makes the game challenging is that there will be many routes, and you have to identify the best route to move the animals while sustaining the most animals and resources. 

There are 15 stages and each stage has 3 – 5 turns from start to finish. In each stage, candidates can collect 3 additional animals or resources at certain points, and choose to multiply (1x, 2x, and 3x) some of their resources. 

If not playing the Plant Defense game, there is a higher probability that you will encounter this game than the mini-game 3 and 4. 

8. Tips to Ace The McKinsey Problem Solving Game

Tip 1: Read the preparation materials and understand the objective of each task

Not reading the preparation materials sent by McKinsey before the game is one of the biggest mistakes candidates can make. You’re not going to fail just because of not reading, but it will eat up an extra 10 minutes of your time.  If you still don’t understand the objective of each game, scroll up to read it through again. Each game, you’ll be tasked with different goals and have to approach it differently. Each game has its own rules and requirements, too.

Tip 2: Don’t get overwhelmed by a large volume of information

The games reflect the complexity of the type of work that consultants must do. Information in the game can get you overwhelmed the first time. Note that there will be too much information but only a limited amount of information can be used. Learning how to ignore inessential information is one of the skills of a future consultant. So, keep calm and always go with a paper to draft anything that comes up in your mind. This way can help you arrange your ideas and tactics to ace each game. Also, you will need to do some math calculations.

Tip 3: Don’t replicate other candidates’ solutions

Other candidates’ solutions will not be applicable to your scenario. The game itself can produce a lot of scenarios, each of which is unique to every candidate to prevent candidates from cheating the game. If you use the same tactics and food chain of former successful candidates, mostly it won’t match your scenario and you are out of the race. 

Tip 4: Learn to compromise

There will be shortcomings in even the best solutions. So don’t worry too much if your plan doesn’t go as expected. The most important thing here is to focus on the time limit and submit your outcome before the time is up. Paying attention to achieve the perfect outcome only wastes your time and resources as a consequence. Especially the Plant Defense game, no matter how you place obstacles to prevent invaders, your particular land will be invaded sooner or later. If you are satisfied with your solution, submit it. 

Tip 5: Find a tranquil place to take the test

Sitting in a place where you would be easily distracted will prevent you from concentrating 100% to come up with the best solutions. If you take the test in the test location set up by McKinsey, it won’t be a problem. If you take the test from your home, remember to remind your mates or family members to keep silent while you’re playing the game. Concentration is very important. 

Tip 6: Check your computer and internet before playing the game

You are given a time period to play the game and must complete it before the deadline set up by the firm. So choose to play when you are most confident and the internet connection is fast and stable. If you lost connection in the middle of the game, contact the technical team (contacts will be provided in the email that McKinsey sends). If lucky, they will arrange your test time to another time, or help you save your data until your internet is reconnected.  

9. Practice with Several Similar Games

Some of the game genres that have many similarities with the McKinsey PSG are City-building games, Tower Defense games, and Grand strategy and 4X games. City-building games are very similar to the Ecosystem Building mini-game while the Tower Defense can be used to practice the Plant Defense game.

9.1 City-building games

This genre includes SimCity series, Caesar series (Zeus and Poseidon, Caesar II, and Emperor ROTK), Anno series (Anno 1404, Anno 2070, etc.), and Cities Skylines. You can leverage these games to practice the Ecosystem Building game. The most significant difference between these games and the PSG is that these games are continuous and you have the right to correct the mistakes if you have – while in the PSG you have limited time and mostly need to complete the system from the start. But it is still a perfect type of game for practicing the Ecosystem Building game due to the similar logic.

McKinsey Problem Solving Game 5

Figure 5: Cities Skylines

9.2 Tower defense games

Kingdom Rush series and Plants vs Zombies series largely resemble the Plant Defense game, with a difference that both games allow you to correct your mistake multiple times before you lose while the Plant Defense game does not. The paths of invaders in both games are fixed and predictable, making it less challenging compared with the Plant Defense game, where the paths of invaders change according to your actions.

McKinsey Problem Solving Game 6

Figure 6: Kingdom Rush 2

9.3 Grand strategy and 4X games

Three series include Civilization series, Europa Universalis series and Crusader Kings series. These games are good practice for the PSG since the logics of Grand strategy and 4X games are quite similar.

Figure 7: Civilization VI

10. PSG Simulation Developed by MConsultingPrep

McKinsey says that no business knowledge is tested and no additional preparation is required since the games are essentially not available anywhere else in the world. However, in order to help candidates get accustomed to the gamification experience and learn more deeply about the objectives as well as complicated rules of the games, MConsultingPrep (MCP) releases a PSG Simulation (can be seen as a mock test for you to practice in advance).

What the PSG Simulation offers:

  • 50-page in-depth strategy guide
  • Template spreadsheets for the Ecosystem Building game
  • A number of practice scenarios produced by the algorithms, with a 95% similarity to the real PSG

PSG Simulation Developed by MConsultingPrep

  • 50-page in-depth strategy guide
  • Template spreadsheets for the Ecosystem Building game
  • A number of practice scenarios produced by the algorithms, with a 95% similarity to the real PSG
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