Assumptions Challenge™

Learn how to stress-test your strategies and pressure-test your plans.


Assumptions Challenge is a foundational Red Team Thinking Tool that will help you identify the stated and unstated assumptions behind your plans and strategies while also providing a rigorous framework for deliberately challenging your thinking in order to overcome cognitive biases, groupthink and other threats to sound decision making.

"Culturally agnostic, along with sector, product, organisation - great tools for use in any organisation."

– Ellie Cloke, United Kingdom

Course Overview


Who is this for?

This workshop is for decision makers, planners and consultants who want to develop and execute more effective strategies and plans in today’s complex and rapidly changing world.


What will I gain?

This is practical, hands-on training that will teach you everything you need to know to begin using Assumptions Challenge in your organization right away and start to identify and challenge the assumptions behind your strategies and plans.


All participants who successfully complete this course will receive RTT Certification in Assumptions Challenge.

Those who complete all of the RTT Core Classes will be awarded formal certification as a Certified Red Team Thinker™.


Assumptions Challenge

19 October, 2022
10:00 AM - 1:30 PM PDT
1:00 PM - 4:30 PM EDT
6:00 PM - 9:30 PM BST

Want to know what time this is for you? 
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This is a live course that will be delivered virtually through the ZOOM video conferencing platform and MURAL collaboration tool. You will be provided links to both application and will need a stable internet connection capable of supporting livestreaming of both audio and video. Please be advised that this course is only open to red teamers who have successfully completed the RTT Boot Camp.

NOTE: The course fee is in US$. While this course is being offered from California, anyone can participate, regardless of the location. The times for this course are listed as GMT.


Red Team Thinking is the world’s leading provider of decision support red teaming for business. In fact, our president literally wrote the book on red teaming. Powered by a cadre of military-trained red team leaders and business strategists, we help companies of all sizes become disruptors in their industries, rather than one of the disrupted. And we can do the same for your business.


Marcus Dimbleby 

Partner and Vice President, Red Team Thinking

Marcus is a former military red teamer who has been sharing these tools and techniques with corporations in the U.K. and around the world since retiring from the Royal Air Force in 2013. In the RAF, he served as a fighter controller and also enjoyed tours with the Royal Marines, Royal Navy and U.S. Marine Corps, with whom he went to Iraq in 2003. An airfield director, strategic and operational planner, and, finally, one of the Air Security Executives responsible for defending the U.K. during the 2012 Olympic Games in London. With extensive experience gained as a senior military officer Marcus seamlessly moved into the business world in London, initially as a senior manager at a major consultancy, then an independent contractor, then business owner and partner – leading on major business transformations predominantly in the financial sector. Along with his military skills and training, Marcus has completed post-graduate studies in Strategic Leadership and Management, as well as Business Management in the areas of performance improvement and change management.

Mark Kiehlmann

Mark’s portfolio career brings together more than three decades of varied and in-depth experience the private, public and third (charity/voluntary) sectors in leadership roles.

Mark initially spent a decade in the private sector, working for FTSE 100 corporations in digital technologies, while also serving with the British Territorial Army, graduating from the Royal Military Academy Sandhurst, serving as a Logistic Officer, and going on to complete the gruelling 23 G Squadron SAS selection process.

Mark continued to serve the community through the following decade, both internationally with a major Non Governmental Organisation and locally by founding an award-winning social enterprise to promote the mitigation of the climate emergency.

Mark’s passion remains at the intersection of technology and human development, with a
focus on data driven decision making, including as a British Cycling coach supporting athletes at national, European and world competition.


"Very topical and relevant particularly in today's environment."

– Jo Hanlon, Australia