Decision Making
Bomb Risk Task
Also called: bomb risk elicitation task, BRET, bomb task, dynamic bomb risk task, risk elicitation task
Measure attitude to risk with one choice: boxes are collected one per second until the participant stops, and one hidden box wipes out the points.
3-5 minUntimed
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- Papers, 2021 to 2025
- 18
- Evidence grade
- D
- Registered clinical studies
- 2
What it measures
Measures attitude to risk with the dynamic bomb risk elicitation task. After Start, boxes from a grid of 100 are collected one each second until the participant stops. Each box adds points, but one hides a bomb (a trap, in the participant's words) that wipes out the round's points, and where it was is shown only at the end. The main score is the number of boxes collected: 50 is risk neutral.
Constructs
- Risk attitude
- Decision making under risk
Research uses
- Behavioral economics research
- Decision-making and risk research
- Individual differences in risk preference
- Within-study group comparison
How the paradigm works
The Bomb Risk Task measures attitude to risk with the bomb risk elicitation task of Crosetto and Filippin (2013). A grid holds 100 boxes, and one of them hides a bomb. In the dynamic version used here, a box is collected each second, in order from the top left, from the moment the participant presses Start until they press Stop. Each box collected adds points, but the round gives nothing if the bomb is among the boxes collected, and where it was is shown only at the end, so the choice is never cut short. Participant screens call the bomb a trap. Each number of boxes from 0 to 100 is a different lottery, so one choice places the participant on a fine scale from risk averse to risk seeking.
More about the paradigm
The session has one practice round, in which no trap is drawn, as in the source, then one check question with feedback and one round that counts. The source recommends a single round: when the task was repeated, choices rose by about 4 boxes. The trap's box is drawn at random for each session. Each box is worth 10 points as standard (1 to 100), and money is mentioned only if the study turns on the payment line. A hidden page pauses the collection. About 3 to 5 minutes.
The main score is the number of boxes collected. Collecting 50 boxes gives the most expected points, the choice of a risk-neutral person; fewer is risk averse and more is risk seeking. The coefficient r of a power utility function for which that number is best, boxes / (100 - boxes), is also reported: below 1 is risk averse. In the source's dynamic version the mean was 46.5 boxes, an r of about 0.85 on average, and choices of 0, 1 and 100 boxes were set aside as likely mistakes; this test flags them for review. Scores support research and do not diagnose.
Scores
- Boxes Collectedcount
- Boxes collected in the round that counts, from 0 to 100.
- 50 is risk neutral; fewer is risk averse and more is risk seeking
- Implied Risk Coefficient (r)score
- The r of a power utility u(x) = x^r for which that number of boxes is best: boxes / (100 - boxes).
- Below 1 is risk averse, 1 is neutral and above 1 is risk seeking
- Trap Collected0/1
- 1 when the trap's box was among the boxes collected.
- Informational: the outcome of the draw
- Points Wonpoints
- Points from the round that counts: the boxes times the points per box, or 0 when the trap was among them.
- Informational
- Practice Boxescount
- Boxes collected in the practice round.
- Informational
- Check Answered Correctly0/1
- 1 when the check question before the round that counts was answered correctly.
- 0 is flagged for review
- Pauses While Hiddencount
- Times the page was hidden while boxes were being collected; the collection paused each time.
- Informational
Use and evidence
18 papers from 2021 to 2025 name this task in their title or abstract. That ranks it 331 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 4 |
| 2024 | 5 |
| 2023 | 2 |
| 2022 | 4 |
| 2021 | 3 |
| 2020 | 0 |
| 2019 | 0 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 2 |
| 2015 | 0 |
| 2014 | 0 |
| 2013 | 1 |
| 2012 | 4 |
| 2011 | 0 |
| 2010 | 0 |
| 2009 | 0 |
| 2008 | 0 |
| 2007 | 0 |
| 2006 | 0 |
| 2005 | 0 |
| 2004 | 0 |
| 2003 | 0 |
| 2002 | 0 |
| 2001 | 0 |
| 2000 | 0 |
Use grade E
Fewer than 30 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 1
- Registered clinical studies using it as an outcome
- 2
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Boxes
- 100 boxes in a 10 by 10 grid, drawn by our code: a closed box, a dashed empty square once collected, and the trap as a dark box with a white cross.
- Collection
- After Start, one box each 1,000 ms, in order from the top left, until Stop or until all 100 are collected. The screen shows the boxes collected and the points they would give.
- Trap
- One box hides a trap (the source's bomb), drawn at random for each session. A round whose boxes include it gives 0 points. Where it was shows only at the end.
- Rounds
- One practice round, in which no trap is drawn, then one check question with feedback and one round that counts.
- Points
- 10 points per box (standard; 1 to 100). Money is mentioned only if the study turns on the payment line.
- Score
- The boxes collected, and the r of a power utility for which that number is best: boxes / (100 - boxes). 50 boxes is risk neutral.
- Pauses
- A hidden page pauses the collection, and the pauses are counted.
Crosetto and Filippin (2013) preferred this dynamic version to choosing a number, because it was easier to understand, and recommended a single round: repeated rounds raised choices by about 4 boxes. Participant screens call the bomb a trap. The scores support research and do not diagnose.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: the scored run's round that counts (bret_round). No number of boxes is correct, so accuracy is not judged against chance. Stopping at 0 or 1 box or collecting all 100, and a wrong answer to the check question, are flagged for review and never exclude.
Why these rules
There is no correct option to compare with chance, so accuracy is not judged against chance. Crosetto and Filippin (2013) set aside choices of 0, 1 and 100 boxes as outliers: 0 and 100 boxes give no points for sure, and 1 box usually means Stop was pressed by mistake. Such a choice can still be real, so it is flagged and never excludes.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Points per box | 10 | 1 to 100 |
| Payment line | Hypothetical points (standard) | Hypothetical points (standard), The study pays for points |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Untimed test: runs on desktops, laptops, tablets and phones. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Bomb Risk Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Crosetto and Filippin, 2013), with the standard settings (points per box: 10; payment line: Hypothetical points). The main score was boxes collected (boxes collected in the round that counts, from 0 to 100).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Crosetto, P., & Filippin, A. (2013). The "bomb" risk elicitation task. Journal of Risk and Uncertainty, 47(1), 31-65. https://doi.org/10.1007/s11166-013-9170-zThe task, its dynamic version and the implied risk coefficient.
- Crosetto, P., & Filippin, A. (2016). A theoretical and experimental appraisal of four risk elicitation methods. Experimental Economics, 19(3), 613-641. https://doi.org/10.1007/s10683-015-9457-9The task beside three other risk elicitation methods.
- Holzmeister, F., & Stefan, M. (2021). The risk elicitation puzzle revisited: Across-methods (in)consistency? Experimental Economics, 24(2), 593-616. https://doi.org/10.1007/s10683-020-09674-8The dynamic task online, and how its choices relate to three other methods.
Source papers
- Crosetto P, Filippin A (2013). The "bomb" risk elicitation task. Journal of Risk and Uncertainty, 47(1):31-65.Paradigm source, Adults
Questions
How long does the Bomb Risk Task take?
About 3 to 5 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Boxes Collected, Implied Risk Coefficient (r), Trap Collected, Points Won, Practice Boxes, Check Answered Correctly and Pauses While Hidden. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Bomb Risk Task used in research?
18 papers from 2021 to 2025 name it in their title or abstract. That ranks it 331 of 395 test families in the ConductCognition test census (use grade E). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Bomb Risk Task have?
In the published research, 0 papers report its test-retest reliability and 2 registered clinical studies use it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Points per box (1 to 100) and payment line (Hypothetical points (standard), The study pays for points). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
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