The AON Gap Challenge is basically a tiny logic grid with a stopwatch
How the no-repeat rule works, why you should solve the question-mark cell first, and where most people waste their six minutes
The name makes the AON Gap Challenge sound like a standard missing-picture puzzle.
It is more specific than that. You get a small grid filled with shapes, a few empty cells and one square marked with a question mark. Your job is to work out which shape belongs in that particular square.
The rule is wonderfully simple: a shape cannot repeat in the same row or column.
Then Aon gives you six minutes.
That is where a tidy little logic problem turns into something much less comfortable. You can understand the rule perfectly and still burn half a minute filling cells that never needed to be filled.
What the Gap Challenge actually asks you to do
Aon’s official practice material describes a 4×4 or 5×5 grid. Some squares already contain shapes, some are blank and one contains a question mark.
No shape may appear twice in any row or column. You can use the empty cells as working space, but the objective is not to complete the whole grid. You only need the shape that belongs in the question-mark cell.
Aon’s current candidate page gives the test a six-minute duration. Its practice document says there is no fixed number of questions: another appears whenever you complete one, and the test may become harder as you progress.
Think of it as a small Latin-square problem. Every row and column must contain a valid set with no duplicates. The target cell sits at the intersection of two sets of restrictions.
That intersection is where you should begin.
Start with the target row and target column
Suppose a 4×4 grid uses four shapes:
- circle;
- square;
- triangle;
- star.
The question-mark row already contains a circle, triangle and star. You do not need to inspect anything else. The missing shape is the square.
Most questions will not hand you the answer quite that cleanly. Still, your first scan should always be:
- Which shapes already appear in the target row?
- Which shapes already appear in the target column?
- Which option is excluded by neither?
Write the two candidate sets mentally, then intersect them.
If the row allows square or star, but the column already contains a star, the answer is square. This is faster and safer than staring at the grid as one large picture.
Use empty cells only when they help the target
The interface may let you fill other blanks. That does not mean you should complete every blank in order.
Work outwards from the question mark.
If the target row is ambiguous, find another empty cell in that same row that can be solved immediately from its column. Filling that cell may force the target. The same idea works in reverse with the target column.
A useful sequence is:
- inspect the target row;
- inspect the target column;
- solve one supporting cell that constrains either of them;
- return to the target.
Stop as soon as the question-mark cell is determined.
Completing the entire grid can feel reassuring, but reassurance is expensive in a six-minute test. A beautiful finished grid earns no extra credit if the question only asked for one shape.
Look for the row or column with one missing shape
When the target itself is not immediately solvable, search for the easiest deduction nearby.
A row with one blank is almost free information. If a 5×5 row already contains four different shapes, the fifth shape is forced. Fill it, then check whether that addition resolves the target column.
Rows and columns with two blanks can also help when one of the candidate shapes is already blocked by the crossing line.
For example:
- a row is missing the triangle and star;
- the first blank’s column already contains a triangle;
- therefore the first blank is the star;
- the second blank must be the triangle.
This is the basic move behind much of the Gap Challenge. You are not discovering a mysterious visual sequence. You are repeatedly asking, “What is still allowed here?”
Do not invent extra pattern rules
Abstract-reasoning practice can actually create a bad habit for this test.
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In a normal matrix puzzle, you might look for rotation, movement, colour changes or alternating counts. In the Gap Challenge format described by Aon, the decisive rule is the row-and-column restriction.
Candidates sometimes waste time searching for a visual story that is not required. They notice that a triangle appears to move diagonally or that dark shapes seem to alternate, then try to extend that pattern.
Come back to the stated rule. Which shapes are present? Which are missing? Which placements would create a duplicate?
The puzzle can become difficult because deductions need several steps, not because the rules have secretly changed.
Keep a candidate pair instead of guessing
Sometimes the target row leaves two possibilities and the target column leaves the same two. That does not mean the question is impossible. It means you need one more deduction.
Hold the candidate pair:
Target is either circle or star.
Then inspect a supporting blank connected to that row or column. If solving it places a circle elsewhere in the target row, your target becomes the star.
This is much better than choosing the option that “looks right”. The shapes are deliberately simple, and once the grid gets busy, familiarity can masquerade as logic.
If your version permits temporary entries, use them carefully. A tentative placement is useful only if you remember that it is tentative. Do not let one assumption quietly become the foundation for three more.
Why the interactive format is harder than an MCQ
The Gap Challenge does eventually ask you to select an answer, but the real work happens inside the grid.
With an ordinary multiple-choice logic question, the options can help. You might test each one, reject the obvious duplicates and arrive at the answer by elimination.
Here, the grid invites you to manipulate intermediate cells. That is helpful, but it also gives you many ways to waste time. You can fill irrelevant spaces, follow a wrong tentative placement or lose track of which entries were given and which you added.
You cannot reliably guess your way through six minutes of these. You need a repeatable solving order.
Mine would be:
Target row. Target column. Nearest forced cell. Back to target.
Short enough to remember. Specific enough to stop you wandering around the grid.
Reading the rule is not enough
On paper, “no repeats in a row or column” is almost embarrassingly easy to understand.
Using it quickly is different.
Practice matters because it trains your eyes to notice the useful line first. After enough grids, a row with one missing shape stands out immediately. Candidate pairs become easier to hold, and you stop feeling compelled to complete the whole puzzle.
A useful practice session has three stages:
- untimed grids where you say each deduction aloud;
- short timed sets where you stop as soon as the target is known;
- review where you identify the first unnecessary move.
That last point is worth tracking. A wrong answer is obvious. A correct answer that took twelve avoidable clicks is also a problem, especially in an assessment with an open-ended number of tasks.
forge has a representative AON Gap Challenge practice test for rehearsing the grid interaction and no-repeat logic. Use your early attempts to reduce unnecessary moves before worrying about raw speed.
A practical six-minute strategy
Before the scored test begins, repeat the tutorial until the interaction is clear. Aon explicitly allows candidates to practise the example task before starting the assessment.
Once the timer starts:
- Locate the question mark.
- Scan its row and column.
- List the remaining candidates.
- Solve the closest forced cell if more information is needed.
- Select the target as soon as it is certain.
- Reset mentally for the next grid.
Do not carry frustration forward. The system may get harder as you progress, so a grid that takes longer does not necessarily mean your method has stopped working.
The best Gap Challenge performance does not look frantic. It looks selective. You ignore most of the grid, make the deduction that changes the target, and move on.
Sources
Aon and gapChallenge are trademarks of their respective owner. forge is an independent preparation platform and is not affiliated with or endorsed by Aon. Test formats can change; follow the instructions in your assessment invitation.
