The free BCG prep mistake I see most often is not laziness. It is starting on someone else's ranked list while BCG's own careers site already publishes free interactive job simulations, a plain-language description of the online case, a Consulting Career Assessment (CCA) briefing, and Associate-led interview guidance. Those pages are the closest thing you will get to the scoring sheet without sitting in the room. Everything else is volume, pacing, or a second opinion.
This guide ranks free material by how close it sits to what BCG itself has put on the record. After you finish, you should know which official links to open first, what the firm will and will not tell you about Casey and the CCA, and how to spend one free week without paying a prep vendor.
Rank free BCG resources by proximity to the firm
Treat "free" as a filter, not a shopping list. A PDF that never appears in a BCG process is still free. It is also a weak substitute for the firm's own practice surface.
| Rank | Resource | What BCG (or its vendor) actually gives you | Use it for |
|---|---|---|---|
| 1 | OneDay@BCG | Free interactive job simulations (strategy, climate, data, and more) | First timed solo run in BCG's own problem language |
| 2 | Case Interview Preparation | Official do/don't list plus Associate Daan Rustige's case-interview walkthrough | Format, listening, and how BCG says reasoning is graded |
| 3 | US Associate process | CCA timing and the "online case (~35 minutes)" for select candidates | Knowing which screen your invitation may name |
| 4 | BCG interview prep brochure | Firm-published case examples and interviewer-side guidance (dated Nov 2018) | Live-case structure and sample problems |
| 5 | Online case practice booklet | Older BCG online-case practice set with worked answers | Exhibit math and timed document cases |
| 6 | MBA consulting club casebooks | School-authored cases, not BCG's | Volume after you know the format |
| 7 | SHL practice tests | Vendor-side numerical practice (CCA runs via SHL for many cohorts) | Pace for timed numerical items |
| 8 | CoachNed free surfaces | Graded reps during the free week; quick math forever | Feedback you will not get from a static PDF |
If a tool is not on this table, ask one question before you invest an evening: does it teach a skill BCG's own pages name (structure, data, quick math, clear communication), or does it mostly teach you how another website likes to talk about BCG?
Start with BCG's interactive OneDay modules
Open OneDay@BCG before you open a casebook. BCG describes more than a dozen free simulations, including Introduction to Strategy Consulting, a Climate and Sustainability module, and a longer Strategy Consulting module built around a fictional tech client with declining profits. These are not interview clones. They are free interactive reps in BCG's preferred problem language: frame the question, work the data, make a call.
Run Strategy Consulting once under a clock. My rule of thumb for a first pass is 40 to 50 minutes of focused work, then a cold rewrite of your recommendation in six sentences: decision, two drivers, one risk, one next analysis, one ask of the client. That rewrite is the skill live interviewers reward. The clicks are just the setup. If you only have half an hour, take Introduction to Strategy Consulting and still force the six-sentence close out loud.
Read what BCG publishes about the online case (Casey)
Candidates call the chatbot-style screen "Casey." BCG's public recruiting copy usually says "online case." On the United States Associate opportunities page, BCG states that a select group of candidates may be invited to complete the online case about two weeks after the application deadline, and that the exercise takes roughly 35 minutes. Candidates who have already taken it are typically not asked to retake it.
That is the firm speaking. Everything else you will hear about question counts, negative marking, or a one-minute video close is candidate report or older practice material. Treat it as useful folklore until your invitation confirms it. BCG has also published an online-case practice booklet (France recruiting, 2019) describing a longer, multi-document format with more than 20 questions in about 45 minutes. Use it for math and exhibit practice. Do not assume that 2019 booklet is the product you will sit in 2026.
What does not change across versions is the skill set BCG names on its case interview preparation page: structure the approach, ask focused questions, analyze data, do quick calculations, and show business intuition. Prep the skills. Let the invitation define the front end.
Read BCG's CCA description before you drill numericals
The Consulting Career Assessment is a separate screen from the online case. On the same US Associate page, BCG describes the CCA as a way to learn more about you beyond the resume, says invitations typically arrive 30 to 90 minutes after you apply, states the assessment takes about 30 to 35 minutes, and gives you 48 hours to finish once the invite arrives. Advanced-degree recruiting pages add that many candidates receive the invite from SHL's TalentCentral address and that a CCA completed within the past year often does not need a retake.
BCG does not publish a universal item list or a pass score on those careers pages. Prep sites invent one. Ignore them. What you can do for free, honestly, is practice the vendor's own style of numerical reasoning on SHL Direct practice tests, then keep your behavioral answers consistent. BCG tells candidates the CCA is multidimensional; it does not tell you to game a personality profile.
Watch BCG's own interview guidance, then one school video
BCG's case-prep page hosts Associate Daan Rustige walking through what the case interview feels like from both sides of the table. Pair that with BCG's published interview tips: listen actively, think structurally, communicate clearly, and avoid overcomplicating the answer. BCG's own LinkedIn cut of that guidance lands the same point in one line: the myth is that cases are about the right answer; the work is making your thinking visible.
For a second free video that is still primary-ish, use a university career center recording with a current BCG consultant rather than a prep-channel mock. The University of Washington Career and Internship Center published tactical tips with a BCG consultant that covers how she actually practiced, what she prioritized under time pressure, and what she stopped doing. You are listening for process, not for a memorized framework.
Add university casebooks and peer cases after the official stack
Once you have finished a OneDay module and read the online-case and CCA language, add volume from MBA consulting club casebooks. Wharton, Darden, Booth, and peer clubs publish free editions most years. They are student-authored. They are not BCG. That is fine for volume after you know the target format.
Use them with a hard rule: one case ends with a spoken recommendation into your phone, not a silent "I would recommend…" typed in the PDF margin. BCG's own prep language keeps returning to communication. Silent case books do not train that.
Peer cases with classmates or alumni are free and closer to the live room than another PDF. Keep the first five peer cases BCG-flavored: candidate-led structure, exhibits on paper, interviewer who pushes back once. Save soft practice for later.
What CoachNed opens for free (stated plainly)
CoachNed is independent of BCG. During the free week (no card), you can run the five-minute first rep at /start, keep /drills/quick-math forever, and sit the Casey-style chatbot case at /casey/urbanbrew-coffee-margin-case. After the week, a recruiting season is $120 or $49 a month if you want more graded cases and drills.
Use those surfaces for what they are: graded feedback on structure, math, and synthesis, not "official BCG content." Official content is still the BCG links above. If you only take one CoachNed free rep during BCG season, take the CopperCup Casey-style case after you have finished a OneDay Strategy module, so you can feel the difference between a firm job simulation and a timed chatbot case flow.
A 90-minute free stack you can run tonight
Here is a concrete assignment with numbers you can reproduce on paper.
Minute 0–5. Read BCG's case-prep "What to Expect" paragraph once. Write three bullets BCG says matter: structure, calculation, communication.
Minute 5–45. Run OneDay Strategy Consulting (or the shorter Introduction module if time is tight). Do not pause for notes mid-flow.
Minute 45–60. Work this original numerical (not a BCG case). Harbor Roast sells 40,000 bags a month at $12. Variable cost is $4.50. Fixed costs are $180,000 a month. Contribution per bag is $7.50. Contribution dollars are 40,000 × 7.50 = $300,000. Profit is 300,000 − 180,000 = $120,000, or a 25% margin on $480,000 revenue. Now price rises 8% and volume falls 5%. New price is $12.96. New volume is 38,000. New contribution per bag is 12.96 − 4.50 = $8.46. New contribution dollars are 38,000 × 8.46 = $321,480. New profit is 321,480 − 180,000 = $141,480. Price-up wins by about $21,500 a month. Say that in 40 seconds without looking at the sheet.
Minute 60–75. Open SHL's numerical practice once, or ten mixed arithmetic drills on /drills/quick-math. Same skill, different skin.
Minute 75–90. Speak a six-sentence recommendation for Harbor Roast into your phone. Play it back. Cut anything that is not decision, driver, risk, or ask.
Ned's rule. Open BCG's free pages before you open anyone else's free list. If a resource cannot show you a careers.bcg.com or media-publications.bcg.com URL, it is secondary, no matter how many stars someone gave it.
Practice this week
Day 1: OneDay Strategy Consulting plus the Harbor Roast math above. Day 2: BCG case-prep page and Associate walkthrough, then a spoken synthesis of yesterday's module. Day 3: read the US Associate CCA and online-case language twice, then one SHL numerical practice. Day 4: CopperCup Casey-style case at /casey/urbanbrew-coffee-margin-case if you are still in the free week. Day 5: one peer case with a friend who has read BCG's do/don't list.
If you want a graded structure warm-up before the peer case, use /start for three typed turns. Keep the rest of the week official and free.
Frequently asked questions
Are BCG's practice cases the same as the real online case?
No. OneDay modules and the dated online-case practice booklet are practice and orientation. The online case that select candidates receive after applying is a separate assessment. BCG's US Associate page is the place to read the current public description.
Is Casey the official name of BCG's online case?
Not on BCG's main recruiting pages. BCG typically says "online case." "Casey" is the nickname candidates use for the chatbot-style version. Prepare for the skills; follow the invitation for the product name and timing.
How long is the BCG CCA?
BCG's US Associate recruiting page says about 30 to 35 minutes, with roughly 48 hours to complete it after the invitation arrives. Exact section design can vary by office and cohort, so your email controls.
Can I prep for free without paying for a case coach?
Yes. BCG's OneDay modules, case-prep page, CCA description, published practice PDFs, SHL practice tests, university casebooks, and peer cases cover the skills. Graded AI practice during CoachNed's free week is optional volume, not a substitute for the official pages.
Should I use ChatGPT as my main BCG prep tool?
Only as a drill partner after you have finished BCG's own materials. A chatbot will invent formats. BCG will not. Keep the firm's pages as the source of truth for process language.
Sources
- Case Interview Preparation | BCG Careers — official case format language, do/don't list, and Associate case-interview walkthrough. Checked 2026-09-24.
- OneDay@BCG | Virtual Experience — free interactive BCG job simulations used here as the primary for-practice surface. Checked 2026-09-24.
- United States Associate Job Opportunities | BCG Careers — CCA timing (about 30–35 minutes, 48-hour window) and online case (~35 minutes) for select candidates. Checked 2026-09-24.
- Interview Process | BCG Careers — high-level consulting interview stages BCG publishes for candidates. Checked 2026-09-24.
- BCG Recruiting Interview Preparation Brochure (Nov 2018) — firm-published case examples and interviewer guidance; dated, still useful for live-case structure. Checked 2026-09-24.
- BCG online case practice booklet (France, 2019) — older online-case practice with timed document questions; format may differ from current invites. Checked 2026-09-24.
- Practice Tests | SHL Direct — vendor numerical practice relevant when CCA invitations come from SHL. Checked 2026-09-24.
- Tactical tips for consulting case interviews (with a BCG consultant) | University of Washington — university-hosted interview with a BCG consultant on prep tactics. Checked 2026-09-24.
CoachNed is not affiliated with BCG or Boston Consulting Group.