Army Officer Selection Board
All you need to know about the Army Officer Selection Board (AOSB)
What is the Army Officer Selection Board?
The Army Officer Selection Board (AOSB) is the primary assessment process used by the British Army to select and assess candidates for officer training at the Royal Military Academy Sandhurst (RMAS). It is a demanding, multi-stage process that evaluates a candidate’s physical ability, intellectual aptitude, leadership potential, and personal qualities.
Success at the AOSB is essential for anyone wishing to become a commissioned officer in the British Army.
What can I expect on the AOSB?
The AOSB is divided into two key stages:
AOSB Briefing (Phase 1)
- Duration: 2 days
- Location: Westbury, Wiltshire
- Purpose: Prepare candidates for the Main Board and conduct a preliminary assessment
AOSB Main Board (Phase 2)
- Duration: 4 days
- Location: Also at Westbury
- Purpose: Full assessment of officer potential
Let’s take a closer look at each of these two stages below.
AOSB Briefing
It is held at the AOSB centre in Westbury, Wiltshire, and typically lasts two days.
Purpose of the Briefing
The AOSB Briefing has two main objectives:
- To prepare you for the more intensive Main Board by familiarizing you with the structure, expectations, and assessment types you’ll encounter later.
- To assess your basic potential as an officer candidate and determine whether you’re ready to move on to the Main Board — or if you should delay to further prepare.
What Happens During the Briefing?
While it’s less intense than the Main Board, the Briefing still involves several key activities:
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Welcome and orientation
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Group discussions
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Planning exercise (introductory version)
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Mental aptitude test (verbal, numerical, and abstract reasoning)
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Basic fitness assessment
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Leadership and teamwork exercises
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Interview with an Army officer
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Detailed feedback session
Possible Outcomes
At the end of the Briefing, you’ll be given a category recommendation:
Category 1
Ready to attend the Main Board
Category 2–4
Encouraged to delay and improve specific areas before progressing
Category 5
Not recommended to continue with officer selection
This feedback helps you understand your strengths and where improvement is needed before facing the Main Board’s full assessment.
Important to Know
Although it’s called a “briefing,” this is not a passive introduction. The AOSB Briefing is your first official assessment, and your conduct, teamwork, communication, and potential are all under observation.
AOSB Main Board
The AOSB Main Board is the final and most comprehensive stage of the British Army’s officer selection process. Held over four days at Westbury in Wiltshire, it is designed to rigorously assess your suitability for officer training at the Royal Military Academy Sandhurst (RMAS).
Only candidates who successfully pass the AOSB Briefing (Phase 1) are invited to attend the Main Board (Phase 2).
Purpose of the Main Board
The goal of the AOSB Main Board is to evaluate whether you have the leadership potential, intellectual ability, emotional resilience, physical fitness, and personal qualities required to become a British Army officer.
This is not just about testing skills—it’s about assessing your character under pressure, your ability to function as part of a team, and your capacity to take command when needed.
What Happens During the Main Board?
The Main Board is a highly structured four-day assessment that includes the following:
Press a box to read more about the subject.
Psychometric Testing
AOSB pschometric testing consists of six separate assessment:
- Mental Aptitude Test
Verbal, numerical, and abstract reasoning - Memory and Attention Test
- Personality Test
- General Knowledge Test
- Current Affairs Test
- Military Knowledge Test
We will take a closer look at each of the six psychometric tests below this chapter.
Physical Test
The Physical Test at the AOSB Main Board is designed to assess your strength, endurance, coordination, and determination. It’s not just about fitness—it also tests your resilience and attitude under pressure.
What to Expect
- Gym-based assessment: Multi Stage Fitness test (Bleep test), Press Ups, and Sit Ups.
- Obstacle course: You’ll tackle a challenging outdoor course involving climbing, crawling, balancing, and teamwork.
Don’t worry if you’re not the fittest — assessors look for determination, teamwork, and a positive attitude as much as raw athleticism.
Planning exercise
The AOSB Planning Exercise tests your ability to analyze, decide, and communicate under pressure. Here’s what to expect:
- Scenario: You’ll receive a written briefing with a fictional situation involving problems and constraints (time, distance, resources).
- Time: You’ll have ~45 minutes to plan, then present your solution in 5 minutes, followed by 10 minutes of questioning.
- What to show:
- Clear mission understanding
- Logical, structured plan
- Prioritization and time management
- Confidence and calmness under pressure
Leadership and Teamwork Tasks
Team Tasks
These include physical and problem-solving challenges, typically set in an outdoor obstacle course environment. You’ll work as part of a small group to overcome tasks using basic equipment (e.g., planks, ropes, barrels). No individual can solve these alone — communication, cooperation, and adaptability are key.
Leadership Tasks
Each candidate takes a turn acting as the team leader. You’ll receive a briefing and must explain the task, assign roles, manage time, and motivate your team. Assessors will observe how well you:
- Plan and communicate your ideas
- Maintain control and focus
- Adapt your leadership style to the team and situation
What Assessors Look For
- Team spirit and supportiveness
- Clear, confident communication
- Logical thinking under pressure
- Willingness to listen and collaborate
- Determination and resilience
Written Test
The Written Test at the AOSB Main Board is designed to assess your written communication skills, clarity of thought, and ability to construct logical arguments. It typically takes place in a quiet exam-style setting and is completed under timed conditions.
What to Expect
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Essay-style task: You’ll be asked to write a short essay or response to a prompt, often on a moral, social, or leadership-related topic.
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Topics: These might involve decision-making, teamwork, leadership, military values, or current affairs.
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Assessment criteria: Structure, clarity, grammar, originality, and how well you express and justify your views.
This is your chance to show you’re thoughtful, articulate, and aligned with the values of a future Army Officer.
Interview
The interview is a core part of the AOSB Main Board and gives assessors a chance to evaluate your character, motivation, and suitability for officer training. It usually lasts around 30–40 minutes and is conducted by a senior officer.
What to Expect
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Background: You’ll be asked about your education, work history, hobbies, and achievements.
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Motivation: Expect questions on why you want to be an officer, your understanding of Army life, and your chosen regiment or corps.
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Awareness: Current affairs, especially those relating to defence, global politics, and UK interests, may be discussed.
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Self-reflection: You may be asked about your strengths, weaknesses, challenges you’ve faced, and lessons you’ve learned.
Be honest, thoughtful, and show maturity and a genuine commitment to service. The goal is to demonstrate potential — not perfection.
Lecture
The Lecture is a key opportunity for you to demonstrate your ability to communicate confidently, clearly, and persuasively in front of a group —an essential skill for any Army Officer. You’ll be asked to prepare and deliver a short talk on a topic of your choice.
What to Expect
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Duration: Typically 5 minutes, followed by a short Q&A session.
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Topic: You choose the subject — ideally something you are passionate about and can speak on with authority and enthusiasm.
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Audience: Your fellow candidates and assessors will be present.
The Lecture tests your presence, preparation, and ability to engage others—core traits of effective leadership.
Assessment and Outcomes
Throughout the Main Board, you are under constant observation by trained assessors, including both military and civilian specialists. Your performance is reviewed holistically across:
- Leadership
- Teamwork
- Judgement
- Communication
- Motivation
- Potential to grow
At the end of the four days, candidates receive a recommendation on whether they are suitable to proceed to officer training at Sandhurst.
AOSB Psychometric Tests
Psychometric testing forms a core part of the AOSB assessment process, providing an objective measure of your cognitive ability, working memory, attention to detail, and personality traits. These tests are administered during both the AOSB Briefing and the Main Board, with increased scope and significance in the latter.
The results are used to assess your mental aptitude for leadership, your ability to process information under pressure, and your suitability for the training and responsibilities of an officer.
Cognitive Ability Tests
Sometimes referred to as the Mental Aptitude Test, the cognitive tests are taken during both the Briefing and the Main Board, and consists of three timed sections: Verbal Reasoning, Numerical Reasoning, and Abstract Reasoning.
Verbal Reasoning
The verbal reasoning section is designed to evaluate your ability to read, understand, and interpret written information, and to make logical decisions based on that information.
This test measures your ability to process text-based material under time pressure, a critical skill for Army officers who must often absorb written orders, interpret reports, and make sound judgments quickly.
In this test, you are required to read a passage and answer a question based solely on the information provided in the text.
Key Features:
- Format: Multiple-choice
- Time: 15 minutes
- Questions: 40
- Skills Tested:
- Understanding written passages
- Making inferences
- Evaluating arguments
AOSB Verbal Reasoning – Example question
Passage:
While technological superiority plays an increasingly important role in modern warfare, it is widely acknowledged within military leadership circles that human factors remain decisive. Morale, cohesion, and the ability of small units to make independent decisions often outweigh purely technological advantages. Historical conflicts such as the Vietnam War and more recent asymmetric engagements in Iraq and Afghanistan have demonstrated that well-equipped forces can still face defeat if they lack adaptability, local understanding, and support from the population. As a result, training in leadership, cultural awareness, and critical thinking has become a priority for officer development programmes in modern armies.
Statement:
A technologically advanced army will consistently win against a less advanced opponent.
Explanation:
Select your answer to display explanation.
The passage clearly argues that technology alone is not sufficient for victory in modern warfare. It cites examples (e.g., Vietnam, Iraq, Afghanistan) where superior forces suffered setbacks, and emphasizes human factors like morale, adaptability, and local understanding. Therefore, the idea that a technologically advanced army will “consistently” win is contradicted by the text, making the statement false.
Numerical Reasoning
The numerical reasoning section is designed to assess your ability to work with numbers under pressure.
As a future Army officer, you may be required to quickly analyze numerical data, interpret operational figures, or make fast, informed decisions based on logistical or resource-based information.
This test primarily features mathematical word problems, as well as questions involving tables and graphs
Key Features:
- Format: Multiple-choice
- Time: 15 minutes
- Questions: 36
- Skills Tested:
- Arithmetic (percentages, ratios, averages)
- Data interpretation (tables, charts, graphs)
- Word problems
AOSB Numerical Reasoning – Example question
A supply convoy is travelling at an average speed of 60 km/h. It must deliver equipment to a forward operating base 270 km away. After every 90 km, the convoy stops for 15 minutes to refuel and check equipment.
How long will the entire journey take, including all scheduled stops?
Explanation:
Select your answer to display explanation.
Travel Time:
Total distance = 270 km
Speed = 60 km/h
Time without stops = 270 ÷ 60 = 4.5 hours (4 hours 30 minutes)
Stops:
270 ÷ 90 = 3 segments → 2 stops (after 90 km and 180 km)
2 × 15 minutes = 30 minutes
Total Time:
4 hours 30 minutes + 30 minutes = 5 hours
Abstract Reasoning
The Abstract Reasoning section evaluates your ability to identify patterns, recognize logical relationships, and solve problems using non-verbal information.
It’s a test of fluid intelligence: your capacity to think logically and solve unfamiliar problems without relying on language or prior knowledge.
In this test, you must identify the common feature shared by the boxes in each of the two sets. Then, determine whether the individual box belongs to Set A, Set B, or neither.
- Format: Multiple-choice
- Time: 12 minutes
- Questions: 70
- Skills Tested:
- Pattern recognition
- Logical progression
- Identifying sequences in shapes and symbols
Which set does the box below belong to?
Explanation:
Select your answer to display explanation.
The correct answer is “Set B”.
The bottom half of the box is a 180-degree rotation of the top half, and therefore belongs to Set B.
Rules of the two sets:
Set A: The bottom half is a mirror image of the top half.
Set B: The bottom half is a 180-degree rotation of the top half.
Free AOSB Practice Test
Try more practice questions for the AOSB Mental Aptitude Test with our free AOSB practice test.
Current Affairs Test
The Current Affairs Test is designed to assess your awareness of recent national and international events, with a focus on issues that may be politically, strategically, or socially relevant to the UK and the Armed Forces.
Key Features:
- Format: Multiple-choice
- Time: 5 minutes
- Questions: 10
In May 2025, the United Kingdom signed a landmark agreement transferring sovereignty of the Chagos Islands to Mauritius. What was the primary strategic objective for the UK in this agreement?
Explanation:
Select your answer to display explanation.
On May 22, 2025, the UK finalized an agreement transferring sovereignty of the Chagos Islands to Mauritius. A key component of this deal was securing a 99-year lease allowing the UK to maintain operational control over the strategically vital Diego Garcia military base. This base is crucial for UK and US defense operations in the Indo-Pacific region.
General Knowledge Test
The General Knowledge Test checks for a broad awareness of academic and cultural topics.
It’s designed to see whether you have a solid foundational understanding of the world — important for officers who must make well-informed decisions and relate to a variety of people and situations.
Key Features:
- Format: Multiple-choice
- Time: 15 minutes
- Questions: 30 – 40
AOSB General Knowledge – Example question
Which of the following UK cities is home to the headquarters of MI5, the United Kingdom’s domestic counter-intelligence and security agency?
Explanation:
Select your answer to display explanation.
MI5, officially known as the Security Service, is based at Thames House in London. It is responsible for protecting the UK against threats such as terrorism, espionage, and cyber attacks.
Military Knowledge Test
This test evaluates your understanding of the British Army, its structure, values, capabilities, and operations.
It helps assess your commitment to the profession and how much effort you’ve made to understand the career you’re applying for.
Key Features:
- Format: Multiple-choice
- Time: 10-15 minutes
- Questions: 20 – 30
What is the name of the British Army’s main battle tank?
Explanation:
Select your answer to display explanation.
The Challenger 2 is the British Army’s primary main battle tank, known for its exceptional armour protection and powerful 120mm rifled gun. It is used primarily by the Royal Tank Regiment and armoured regiments within the British Army.
Personality Test
The Personality Test is an important part of the AOSB Main Board. It is not a test you “pass” or “fail” — instead, it is used to build a psychological profile that gives the assessors a better understanding of how you think, behave, and lead. This profile complements the rest of your performance, including interviews, group exercises, and leadership tasks.
The British Army is looking for self-aware, emotionally stable, resilient, and team-oriented individuals with leadership potential. The personality test helps assess whether your behavioural traits align with these expectations.
- Type: Self-report questionnaire
- Estimated Length: Around 200 statements
- Time: Approximately 30–40 minutes
- Style: Statements rated on a Likert scale (e.g., “Strongly Agree” to “Strongly Disagree”)
You may be asked to respond to statements such as:
- “I enjoy taking charge in group situations.”
- “I find it easy to remain calm in stressful environments.”
- “I prefer to work alone rather than as part of a team.”
- “I follow rules closely, even when others do not.”
Traits Likely Measured
While the British Army does not publicly disclose the exact personality model used, it likely assesses dimensions similar to those in occupational psychology, such as:
- Emotional stability (how you handle stress and pressure)
- Conscientiousness (reliability, organisation, discipline)
- Extraversion and sociability (leadership presence, communication)
- Openness to experience (adaptability, willingness to learn)
- Integrity and honesty (moral judgement, self-control)
- Leadership and assertiveness
- Team orientation and collaboration
The test may also look for inconsistencies in your responses or patterns that suggest exaggeration or impression management (i.e., trying too hard to give the “right” answer).
AOSB Psychometric Test Preparation
Preparing for the AOSB (Army Officer Selection Board) is a challenge — and your performance on the psychometric tests plays a key role in your success. To help you build confidence and perform at your best, we offer tailored AOSB test prep materials that mirror the style, format, and difficulty of the official assessments.
Our materials cover:
- Verbal Reasoning
- Numerical Reasoning
- Abstract Reasoning
- Memory and Attention
- General Knowledge
- Military Knowledge
- Current Affairs
- Personality Test
Use our AOSB preparation course to practice under timed conditions, build confidence, and improve your speed and accuracy.
Tips for Passing the AOSB
We’ve collected a detailed list of practical tips from past AOSB candidates to help you prepare with confidence.
Read our article:
Top AOSB Tips from Past Candidates: What They Wish They Knew.
Top Candidate Tips
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Key Features:
- Format: Multiple-choice
- Time: 5 minutes
- Questions: 10
Army Office Selection Board Preparation
Not simply practice questions but accurate AOSB preparation materials that simulate the real thing.
700 practice questions
- 220 Numerical Reasoning
- 160 Verbal Reasoning
- 295 Abstract Reasoning
- 100 General & Military Knowledge
- Memory and attention practice
- Simulated Personality Test
Explained answers
Fully explained solutions teach you why an answer is correct, increasing your overall performance.
Test statistics
Detailed test statistics, progress reports, and performance charts help you track your progress.
Simulate the real test
Run two full-length Mental Aptitude Tests to simulate real AOSB test conditions.