Written Case Interview: BCG and Bain Format, Slides, Worked Example

A written case interview gives you a pack of exhibits, a fixed prep window and a few client questions, then asks you to present a short slide recommendation and defend it in Q&A. BCG's Amsterdam office lists a 2.5-hour written case in its final round (BCG Netherlands careers page, official, checked September 2026). Bain, Oliver Wyman, Deloitte and PwC Strategy& are also reported to use written cases in some offices, with prep windows from 30 minutes to about 2 hours. This guide covers the format by firm, a timed method for the data pack, how to structure slides, and a full worked example from exhibits to Q&A.

What is a written case interview?

A written case interview is a consulting case you solve alone from printed or digital exhibits, instead of talking it through with an interviewer. You get a client situation and usually three or four questions, analyze the pack under a time limit, fill in or build a few slides, then present to one or more interviewers who challenge your numbers and logic. It tests the same problem solving as a live case, plus triage (finding the few exhibits that matter) and written synthesis (turning analysis into slide headlines).

The core skill underneath every version is reading one exhibit fast and saying what it means for the decision. You can build that skill in short reps with free chart-reading drills on Road to Offer before you run full timed packs. For how chart reading works in a live case, see case interview data interpretation.

Which firms use written case interviews, and in which offices?

Only some offices at each firm use a written case, and firms rarely publish the format. Where an official page exists, it wins. Everything else below comes from candidate-report guides, labeled with the month they were updated.

BCG written case format

BCG's Amsterdam page is the clearest official statement: the final round has a 45-minute recruiter interview, two 60-minute case interviews and a 2.5-hour written case, for Visiting Associate through Consultant roles (BCG Netherlands, checked September 2026). BCG's Sweden page, by contrast, describes two interview rounds with interactive case discussions and doesn't mention a written case (BCG Sweden, checked September 2026). That gap is exactly why you confirm with your recruiter.

Candidate-report guides describe the rest of the BCG format (Hacking the Case written case guide, updated July 2026):

• Pack: about 40 slides of charts, tables and report extracts, opening with a simulated partner email that asks 3 to 4 questions.
• Output: blank slides, with 3 to 5 slides expected.
• Tools: a calculator is allowed, but you typically can't write on the information pages because BCG reuses them.
• Presentation: about 40 minutes to present and discuss, split roughly evenly between your presentation and questions.
• Offices named in reports: US, UK, Netherlands, Sweden and South Africa.

MConsultingPrep's written case guide gives a slightly wider range, 40 to 50 documents and 40 to 50 minutes of presentation and questions (MConsultingPrep, undated, checked September 2026). Treat both as ranges, not rules.

Bain written case format

Bain's own case interview page describes live cases and doesn't mention a written case (Bain case interview preparation, checked September 2026). Candidate-report guides describe a shorter, more structured exercise (Hacking the Case, updated July 2026):

• Pack: 20 to 30 slides describing the client situation.
• Output: 3 to 5 pre-filled slide templates with titles, partial charts or blanks you complete by hand. MConsultingPrep reports 4 to 6 templates.
• Time: 55 to 90 minutes depending on office. MyConsultingOffer reports 55 minutes (MyConsultingOffer, updated January 2025).
• Tools: no calculator, and no writing on the information slides.
• Presentation: 30 to 40 minutes to present and take questions.
• Offices named in reports: mainly Europe, Asia and Greater China, less common in North America.

Bain's general hiring-process page also lists a take-home written assignment, usually with three days and sometimes a presentation, as a step for some roles without naming which ones (Bain interviewing, checked September 2026). For take-home rules and delivery, use the written case and presentation playbook.

Oliver Wyman, Deloitte and PwC Strategy&

• Oliver Wyman: some candidates get a written case, also called a case presentation, in the final round, with about 30 minutes to review the pack and 30 minutes to present and answer questions. Not all offices include it (Hacking the Case Oliver Wyman guide, updated July 2026). MyConsultingOffer reports it only for selected locations (MyConsultingOffer, updated January 2026).
• Deloitte: certain offices include a written component. Some hand over materials 2 to 3 days early, others run a timed session, and some final rounds add a group case (Hacking the Case, July 2026). If yours pairs the written case with a group exercise, the group case and inbox playbook covers that half.
• PwC Strategy&: candidates receive a data pack and present a recommendation (Hacking the Case, July 2026). MConsultingPrep reports that PwC can send documents 48 hours before the presentation (undated).

If your invitation lists several exercises in one day, start from the consulting assessment center guide to route each one.

How is a written case different from a live case interview?

In a live case the interviewer controls pacing, hands you exhibits one at a time and redirects you when you drift. In a written case you get everything at once, and nobody tells you which exhibits matter. That changes four things:

• Triage is scored. A pack can hold dozens of pages, and most of it is context or noise. Missing the one exhibit that drives the answer hurts more than skipping five background pages.
• Mistakes compound silently. A wrong number in minute 20 flows into every slide, and nobody catches it until the presenter's Q&A.
• Writing is evaluated. Slide headlines are read as client communication. "Revenue fell 12%" is a fact; "Revenue fell 12% because corporate clients churned, so retention is the problem" is a conclusion.
• Q&A is a separate test. Interviewers probe the assumptions behind your headlines, so solid slides can still lose points if you can't defend them.

The underlying scoring themes overlap with live cases, so the case interview scoring rubric is still a useful checklist.

What is the Map-Mine-Message-Defend method?

Map-Mine-Message-Defend is a four-phase loop that fits any written case window. Most candidates fail by reading too long and writing too late, so the method forces the switch from reading to writing before half the time is gone.

1. Map: read the questions and deliverable, then scan every exhibit title and axis. Tag each exhibit to a question.
2. Mine: read the two to four exhibits that answer the questions, run only the calculations that change the answer, and write a one-line implication after each.
3. Message: write every slide headline as a full-sentence conclusion, then fill in the evidence underneath.
4. Defend: list the two weakest assumptions and prepare a 30-second answer for each.

Suggested time splits for the three reported window lengths (our planning guide, not a firm rule):

In every column, Map plus Mine ends before the halfway mark, so at least half the window is left for writing and preparing your defense. If you're still reading at the halfway point, start headlines with what you have.

How do you read a written case data pack without running out of time?

Read by question, not by page order. The pack order reflects how the case writer assembled documents, not what your answer needs.

Step 1: Write the questions down (Map)

Copy the partner's three or four questions onto scratch paper, one per line, and note the deliverable (blank slides, pre-filled templates, a memo). If the prompt says "the fund wants to know whether to bid," every exhibit gets judged against that decision. Answering a different question than the one asked is the fastest way to fail.

Step 2: Scan titles and axes only (Map)

Flip through every page reading only the title, axis labels, units and any callout box. Next to each question, write the exhibit numbers that could answer it. Don't read body text yet. By the end you should know where the answer probably lives.

Step 3: Read the priority exhibits properly (Mine)

Read the two to four exhibits tagged to the core question. For each, use a three-part read:

• Describe: what does the chart literally show? ("EBITDA fell from €12.0M to €9.6M.")
• Explain: what drives it? ("All the decline comes from 12 new clinics; mature clinics are flat.")
• Imply: what does it mean for the decision? ("The drop is a ramp-up cost, not a broken business.")

Write the implication line next to the exhibit number. Those lines become your headlines later.

Step 4: Check the rest for contradictions (Mine)

Skim the remaining exhibits with one question in mind: does anything here reverse my working answer? If not, move on. If you're not allowed to write on the information pages, keep your exhibit map on scratch paper so you don't re-read.

Which exhibit types usually matter most:

Reading one exhibit fast and stating its implication is a skill you can rep on its own. The drill below serves a live chart question from the Road to Offer drill engine; it trains the Describe-Explain-Imply read on a single exhibit, not a full written case pack.

Which calculations belong in a written case?

Do fewer calculations, and finish each one. Eight half-checked numbers on slides give interviewers eight places to catch you. Three complete calculations, each with a formula, the numbers plugged in and a sense check, are stronger.

Use this filter before you calculate anything: would a different result change my recommendation? If not, skip it.

For each calculation you keep:

1. Write the formula in words first. "Implied multiple = asking price ÷ EBITDA."
2. Plug in rounded numbers. €150M ÷ €9.6M.
3. Solve without a calculator if the firm reports banning one. 9.6 × 15 = 144, and 6 left over is about 0.6 more, so roughly 15.6x.
4. Sense-check the size. A 15.6x multiple against 9x to 11x comps should make you ask why, not just report it.
5. Write the implication. "At today's profit the price looks expensive; the question is whether today's profit is normal."

No-calculator packs reward a few habits: round to two significant figures early, turn divisions into multiplications you can check, and express changes as percentages of the base you'll cite. The case interview math tips guide covers these shortcuts, and timed math drills help if your office bans a calculator.

How should you structure written case slides?

Structure depends on what you're handed. Reports describe blank slides at BCG and pre-filled templates at Bain (Hacking the Case, July 2026), and the job is different in each.

Blank slides: build an answer-first storyline

A reliable default for 3 to 5 blank slides:

1. Answer slide: the recommendation plus three supporting reasons, each with a number.
2. Evidence slide(s): one reason per slide, with the one chart or table that proves it.
3. Risks and next steps: two or three specific risks, each with a mitigation, and actions the client can take this quarter.

If one reason needs no chart, fold it into the answer slide and stop at three slides. Add a slide only when it carries a new conclusion.

Pre-filled templates: complete the story you're given

When slide titles or chart frames are pre-printed, the storyline is already set. Your job is to find the data for each title, finish the calculation, and write a short conclusion in the space provided. Check each completed slide against its title before moving on, because a correct number under the wrong title still reads as a miss.

Anatomy of one slide

• Headline: one full sentence stating the conclusion, with a number.
• Body: one chart or table, drawn simply. Label units and axes.
• Callouts: two or three short notes that point at the data proving the headline.
• Source line: the exhibit number you took it from, so you can find it in Q&A.

Headline examples: topic label vs conclusion

Write the headline before you draw the chart. If you can't write it, you don't know yet what the slide proves.

For more synthesis phrasing, see case interview synthesis. If your headline drafts keep coming out as topic labels, a short synthesis rep trains the habit of leading with the conclusion. It's a one-answer drill, not a slide builder.

What does a full written case look like from pack to slides?

This is an original practice case built to show the method end to end. Every number is an illustrative exhibit value, not data from a real firm's written case.

The pack and the partner's questions

A private equity fund is considering buying a regional chain of 52 physiotherapy clinics. The seller is asking €150M. You have 2 hours and blank slides. The partner email asks:

1. Why did profit fall between 2023 and 2025?
2. Is the decline temporary or structural?
3. Should the fund bid, and at what price?

The pack holds 12 exhibits. After a 10-minute Map pass, the tags look like this:

Mine: the numbers that change the answer

Exhibit 2, the headline problem. Revenue grew from €80M to €96M (+20%), but EBITDA fell from €12.0M to €9.6M (−20%). Margin dropped from 15% to 10%.

Exhibit 3, the split. The 40 clinics open before 2023 each earned €2.0M of revenue in both years at a 15% margin, so they produced €80M and €12.0M both times. The 12 clinics opened in 2024 and 2025 earned €16M in total (about €1.33M each) and lost €2.4M.

• Check: €80M + €16M = €96M revenue, and €12.0M − €2.4M = €9.6M EBITDA. The whole decline sits in the new clinics.
• Implication: the mature business is flat and healthy; the drop is ramp-up cost.

Exhibit 4, is it temporary? Therapists in new clinics are at 60% utilization against 85% in mature clinics. The cohort history shows earlier clinics reached €2.0M in revenue by their third year.

• Implication: the gap is empty appointment slots, which normally close as clinics mature.

Normalized EBITDA, two cases.

• Base case: all 52 clinics reach mature levels. 52 × €2.0M = €104M revenue at 15% = €15.6M EBITDA.
• Conservative case: new clinics reach only 80% of mature revenue (€1.6M each) at a 12% margin. 12 × €1.6M = €19.2M revenue, EBITDA €2.3M. Add the mature €12.0M for €14.3M EBITDA.

Exhibit 9, what the price implies. Comparable deals traded at 9x to 11x EBITDA.

• On today's €9.6M: €150M ÷ €9.6M ≈ 15.6x, well above comps.
• On the base case €15.6M: €150M ÷ €15.6M ≈ 9.6x, inside comps.
• On the conservative €14.3M: €150M ÷ €14.3M ≈ 10.5x, near the top of comps.
• At a 10x midpoint, the conservative case supports about €143M and the base case about €156M.

Exhibit 5, the main risk. 30% of revenue comes from one statutory insurer with a tariff review due. A 5% tariff cut on that share of the base-case revenue removes 5% × 30% × €104M ≈ €1.6M of EBITDA, if costs don't move.

What was skipped. Exhibits 8, 10, 11 and 12 didn't touch any of the three questions. Exhibit 6 (patient survey) was skimmed: it only matters if new clinics score worse than mature ones, which would point to a demand problem rather than ramp-up.

Message: the three slides

Slide 1 headline: "Bid €140M plus an earnout of up to €15M: profit fell only because 12 new clinics are still ramping"

• Mature clinics held €12.0M EBITDA at 15% margin; all of the €2.4M decline sits in new clinics.
• New clinics run at 60% therapist utilization vs 85%, and earlier cohorts matured by year three.
• €150M looks expensive at 15.6x today's EBITDA but is 9.6x to 10.5x normalized EBITDA.

Slide 2 headline: "The conservative case supports about €143M, so pay the rest only if new clinics mature"

• Chart: a simple bar of EBITDA today (€9.6M), conservative (€14.3M) and base (€15.6M), with implied multiples at €150M.
• Callout: earnout pays up to €15M if 2027 EBITDA reaches €15.0M, which is close to the base case.

Slide 3 headline: "Two risks could cut normalized EBITDA by €1.6M or more; diligence the insurer tariff first"

• Tariff review: a 5% cut on 30% of revenue removes about €1.6M EBITDA. Mitigation: model the review outcome before signing and link part of the price to it.
• Therapist wages: wages are 55% of revenue in Exhibit 4, so each point of wage inflation not passed on costs about €0.57M at €104M revenue. Mitigation: test hiring pipeline and pricing power in new cities.
• Next steps: confirm cohort maturity data clinic by clinic, get a view on the tariff review, and check that new clinics' patient satisfaction matches mature clinics.

Defend: the prepared Q&A answers

"Why not value the business on today's €9.6M?" "Because the mature clinics didn't decline at all. Exhibit 3 shows all of the drop comes from 12 clinics in their first two years, and Exhibit 4 shows their therapists are at 60% utilization. Valuing on €9.6M treats a ramp-up cost as permanent."

"What if the new clinics never reach mature levels?" "That's the conservative case: 80% of mature revenue at a 12% margin gives €14.3M, or 10.5x at the asking price. That's why I'm not recommending €150M upfront. At 10x it supports about €143M, so €140M upfront keeps us inside that and the earnout only pays if the base case happens."

"What if the tariff cut and the slow ramp both hit?" "Then normalized EBITDA drops to about €12.8M, and at 10x the business is worth about €128M, below the €140M offer. That's the €12M of downside I'd diligence first, and why the tariff review is the first next step."

"You skipped the patient survey. Could it change your answer?" "It could if new clinics score lower than mature ones, because that would suggest weak demand rather than ramp-up. I'd check that before signing. If they score the same, the recommendation holds."

The fourth answer matters as much as the first three: interviewers respect a candidate who names what they skipped and when it would matter. For deal-specific structures, see the private equity case interview guide and the PE due diligence framework.

Written cases end in a spoken defense, and the closest practice for that part is a full case you answer out loud. This one is a healthcare acquisition case run live with AI scoring, not a written pack.

How do you present and defend the slides in Q&A?

Reports describe about 40 minutes at BCG, split roughly evenly between presenting and questions, and 30 to 40 minutes at Bain (Hacking the Case, July 2026). Keep the presentation short and prepare hardest for the questions.

Presenting: lead with the answer slide, walk each headline in one or two sentences, and point at the exhibit number behind each number. Don't read the slide body aloud.

The three probes to expect:

• Source challenge: "Where does that number come from?" Name the exhibit and say whether it's client data, a forecast or your assumption.
• Assumption challenge: "What if that assumption is wrong?" Give the sensitivity you prepared and say whether the recommendation changes.
• Alternative explanation: "Couldn't this be something else?" State the alternative, the evidence that rules it out, and what you'd check if it can't be ruled out.

For talk tracks, delivery and deeper Q&A defense, use the written case and presentation playbook. For general spoken clarity, see case interview communication tips.

What are the most common written case mistakes?

• Reading every page with equal care. You run out of time before slides. Map first, then mine only the tagged exhibits.
• Starting slides too late. If Map plus Mine runs past the halfway mark, stop reading and start headlines with what you have.
• Topic headlines. "Market overview" says nothing. Every headline states a conclusion and a number.
• Conditional non-answers. "It depends on regulation" isn't a recommendation. Recommend, then say what would change your mind.
• Unchecked arithmetic. One wrong base number spreads to every slide. Sense-check each result against the exhibit it came from.
• Generic risks. "Execution risk" tells the client nothing. Quantify each risk and pair it with a mitigation.
• Ignoring the deliverable. Filling extra blank slides when the firm handed you templates, or skipping a question the partner asked, reads as not following instructions.

How should you practice for a written case interview?

Practice the full timed pack at your office's reported window, and train the component skills in short reps between packs. A one-week plan:

Where to get packs: use any practice material your recruiter sends first. Hacking the Case reported in July 2026 that BCG's own practice written case asks for 3 to 5 slides in 2 hours; when we checked BCG's case interview preparation page in September 2026, it no longer linked a written case file (BCG case interview preparation). A workable substitute is a long casebook case turned into a pack: print every exhibit, hide the solution, set your firm's timer and build the slides.

How Road to Offer helps: Road to Offer doesn't run written case packs or grade handwritten slides. It trains the pieces inside one. The drill bank holds 550+ drills across six types, including chart reading, synthesis and case math, each scored with AI feedback. For the spoken defense, the case library has 71 AI-scored cases you answer out loud, and your first full case is free. Pair free chart-reading drills during the week with the timed packs above, and the reading and headline phases get faster before interview day.

Sources

Checked September 14, 2026, unless noted.

• BCG Netherlands careers page, interview process (official): careers.bcg.com/global/en/locations/the-netherlands
• BCG Sweden careers page, interview process (official): careers.bcg.com/global/en/locations/sweden
• BCG case interview preparation (official): careers.bcg.com/global/en/case-interview-preparation
• Bain case interview preparation (official): bain.com/careers/hiring-process/case-interview
• Bain interviewing, hiring process (official): bain.com/careers/hiring-process/interviewing
• Hacking the Case, written case interview guide (reported, updated July 7, 2026): hackingthecaseinterview.com
• Hacking the Case, Oliver Wyman case interview guide (reported, updated July 6, 2026): hackingthecaseinterview.com
• MyConsultingOffer, Bain written case interviews (reported, updated January 2025): myconsultingoffer.org
• MyConsultingOffer, Oliver Wyman case interview (reported, updated January 2026): myconsultingoffer.org
• MConsultingPrep, written case interview guide (reported, undated): mconsultingprep.com
• The physiotherapy clinic example on this page is original illustrative practice.