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How to configure Q&A CAPTCHA.

Description: This describes how to correctly configure the Q&A CAPTCHA to show on the registration page and help stop automated registrations. It can also be used as an 'invitation only' protection.

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How to configure Q&A CAPTCHA

Q&A (Question & Answer) CAPTCHA was incorporated in phpBB3.0.6 and versions thereafter. It allows the administrator to set a question of their choice to prevent automated registration of spam accounts and can also be used to make the board invitation only if that condition is required.


  • Administration Control Panel > General tab > Spambot countermeasures > Installed plugins > click the dropdown box and select Q&A (it will be greyed out)
  • Click the configure button then click add.
  • Add your question and answer (you need a Q&A for each language you have installed) click submit.
  • Click “back to previous page” then click “back”
  • Select Q&A from the dropdown box (again)
  • Click submit at the bottom of the page.
  • Done.

You only need one question. If you think the bots have figured it out you can just change it to another.

To make it an effective antispam measure you need to make it a question you cannot search the answer to.

DO NOT use questions like 'What colour is the sky?' or 'What is 2+2?'.

You need something like (and do not use these exact questions or exact wordings)
Enter the first 4 letters of the word GOLDFISH
Write the word GOLDFISH backwards

'Requirements not met' error
If you see this message The plugin cannot be selected as its requirements are not met then that means you have more than one language installed but you have not set the question in every language.

On the page where you write the question and answer there is a drop list for all of the languages installed in the board. You must choose each one in turn and enter the question and answer.

Using Q&A CAPTCHA for an 'invitation only' board

If you have a private board that you have a known membership for and you only want those specific users to join (for example a local club or committee) then you can also use the Q&A to restrict registration to those users.

Set the question to be something like 'Enter the code that you have been emailed' and then simply send it to the users that you want to have access.

DO NOT make the code a dictionary word. This would make it guessable (although unlikely) so use a random set of numbers and letters.

Only the people who know the exact code will be able to register. Now, granted, you would have no control over them sending the code to other people that you did not want it to go to but private boards are more likely to have a certain amount of common sense about them and the members will be known. You could always incorporate the new member post limit to make the first post require approval to add an extra level of security or use the Support Toolkit to create the accounts first.