Sources: the official FAQ and blog posts.
See also the official privileges page for bounties.
What is a bounty?
A bounty is a special reputation award given to answers. This feature was designed to motivate answerers, and help questions get the answers they deserve.
Bounty awards are funded by the personal reputation of the users who offer them. The award can generally be anywhere from 50 to 500 reputation, in 50 point increments.
While you do not need to be the owner of a question to start a bounty on that question, only one bounty can be active on a particular question at once.
As of June 2010, the bounty system is decoupled from accepting an answer.
How can I find questions that have a bounty attached?
Questions with an active bounty appear with a special icon in all question lists, and are also visible on the home page's "Bountied" tab. Questions in that tab are sorted by the amount of time left on their bounties. The closer a bounty is to expiring, the higher it will be on the list.
How do I start a bounty? When can I start a bounty?
A bounty can be started on any question 48 hours after the question was asked, provided the question isn't closed, locked, or deleted.
To start a bounty, click on the "Start a bounty" link at the bottom of an eligible question. (The link is underneath the comments, not in the 'post menu' like "Share" and "Edit".) The bounty panel will open. Use the dropdown to allocate the bounty amount -- anywhere between 50 and 500 reputation, in 50 point increments. Also, specify a canned reason why you are starting the bounty from a dropdown, and type an optional further explanation.
You must have at least 75 reputation to start a bounty, and at least as much reputation as the bounty amount.
The bounty award will be subtracted from your reputation when the bounty is started, not when it is awarded.
Why is the system requiring me to choose a bounty amount that's higher than the minimum?
For most questions, you can start a minimum bounty of 50 reputation. There are some cases where the system may require a higher amount, though:
- If you have already answered the question before, the minimum bounty offer is 100.
- If you have already offered a bounty on the question before, the minimum offer is double your last offer (see below).
Can I use Markdown formatting in the bounty remarks? Can I edit the remark?
Bounty notices support the Markdown mini format used for comments, with the addition of double line (paragraph) breaks.
The following markup syntax features are allowed:
_italic_ and **bold** text,
inline `code in backticks`,
and [basic links](http://example.com).
You cannot edit the remark, so validate carefully before saving.
How long is the bounty period?
7 days, or 168 hours.
As of June 2011, bounty offerers may award bounties up to 24 hours after the bounty period ends (known as the grace period), to allow them to evaluate answers posted at the end of the bounty period. During the grace period, there will be no indication in the questions lists (e.g. front page, bountied tab) that the question has a bounty, as confirmed here. However, answers posted during the grace period can still be awarded the bounty.
Note that even if no one else answered during the bounty period, the grace period is still in effect for 24 hours.
How do I award a bounty?
A bounty can be awarded 24 hours after the bounty was started. You can award the bounty to any answer posted by anyone else, even an answer that has already been awarded one or more bounties (including by you).
To award the bounty manually, click on the +50 (or whatever bounty amount was allocated) button on the left side of the answer you want to award:
Can I award a bounty to my own answer?
No. This used to be possible, but it has been disabled. The +50 (or whatever bounty amount was allocated) award button simply won't show beside your own answers.
(On past bounties awarded to one's own answers, the user would not get the reputation back, and the bounty would be displayed as +0, “this answer has been awarded bounty worth 0 reputation”.)
Can I award a bounty to an old answer?
Yes, you can award your bounty to any answer on the question. This makes it possible for users to reward particularly good answers with more rep than a standard upvote would provide.
To indicate that your bounty will be awarded to an existing answer, choose "Reward existing answer" when asked "Why are you starting this bounty?"
Keep in mind, that the bounty can be awarded only after a minimum of 24 hours, after starting the bounty. It is suggested that you wait until the grace period to award the bounty, as due to the additional attention a bounty gives, the answer may receive more upvotes.
If I offer a bounty on someone else's question, can I award the bounty to the author's answer?
Yes, a bounty can be awarded to any answer except one posted by the person offering the bounty.
This means that if you offer a bounty on someone else's question, and the author of that question posts a self-answer, you can award the bounty to their answer.
After awarding the bounty, can I remove it or move it to another answer at a later time?
No, awarding is permanent. (But you're warned about that when actually awarding the bounty.)
What happens if there's no answer after the bounty period?
If, after the end of the bounty period, a question has no answers, the bounty will expire and the reputation will disappear.
Part of what you're "paying for" with a bounty is for higher question visibility and increased answerer motivation. A bounty does not guarantee a response and is not refunded if none are received.
What happens if I feel my question is still unanswered? / What is automatic awarding?
Approximately 24 hours after the end of the bounty period (once the grace period ends), if the bounty starter has not manually awarded the bounty, the bounty may be awarded automatically. This is so that if the bounty owner chooses not to award the bounty to any answer, those who answered the question based on the bounty will still be rewarded for their effort.
If the author offered the bounty, and accepted an answer that was posted after the bounty was started, that answer is awarded the full bounty.
Otherwise, either all or half of the bounty will be awarded to the highest-scored answer among those which meet all of the following:
- They were posted after the bounty was started, and
- They have a score of at least 2 (at the time the automatic awarding takes place), and
- They were not written by the bounty starter.
If the chosen answer was accepted by the question owner, it will receive the full bounty. Otherwise, it will receive half the bounty. If two eligible answers have the same score, the older answer is chosen.
If no answer can be automatically awarded the bounty under any of the above two schemes, the bounty is not awarded to any answer, and is not refunded to the bounty starter.
Are bounties exempt from the 200 points/day reputation limit?
Yes, bounty offers and awards are exempt from the daily reputation cap.
How does Community Wiki mode affect bounties?
Bounties are not affected by community wiki mode. When you award a bounty to an answer marked community wiki, the reputation bonus will be awarded to the user who posted the original revision of the answer.
How does user deletion or post dissociation affect bounties? / Can I award a bounty to an answer from a deleted user or one where the author was dissociated?
If a user who has earned a bounty is dissociated from that answer or gets their account deleted, the reputation will disappear permanently. Even if the user recreates their account, the reputation will not be reinstated, because account deletion also dissociates all posts.
Bounty owners can award bounties to answers posted by deleted or dissociated users, and the answer will be marked as having earned a bounty, but the bounty reputation will not be awarded to anyone. This applies even if the answer's owner still exists.
Can I offer a second bounty after the first one has expired? / Can I raise my bounty?
You can offer as many bounties on a question as you want. However, only one bounty can be active on a question at a time. Moreover, any user may have at most 3 concurrent bounties.
You cannot later on decide you want to award more reputation after starting your bounty: once you start it, the reputation amount is locked in until the bounty is over. If you later decide to award more reputation, start a second bounty after the first one ends.
Note that if you offer more than one bounty on the same question, you will have to double the amount each time (or more). That is, if your first bounty was worth 50 reputation, your second bounty on the same question will have to be for at least 100, your third for at least 200 and so on. If you've already offered a bounty for 250 or more reputation, you can still offer more bounties for 500 (the maximum amount) as long as you like (or as long as you have the rep). This doubling applies only to bounties by the same user on the same question.
What happens if a bounty question is closed or deleted? / Why can't I vote to close or migrate a bounty question?
Bounty questions cannot be closed directly.
However, diamond moderators can clear bounties, which would effectively remove the bounty and clear its history. The bounty owner's reputation would be recalculated as if they had never placed that bounty (effectively refunding the bounty amount to the user who started the bounty). This would then allow it to be closed, migrated, or deleted like any other question. (source)
How does post locking affect bounties?
Comment locks and policy locks
Comment locks and policy locks do not impede starting and awarding bounties, and posts locked with one of these two options aren't considered "locked" for the purposes of the below subsections.
Other types of locks (except historical locks)
You cannot start bounties on questions that are locked. However, in most cases, if you started a bounty on a question before it got locked, you can still award the bounty.
Regardless of the question's locked status, you can't award bounties to answers that are locked. However, if a locked answer meets the criteria for automatic awarding, it can receive an automatic award.
You cannot start bounties on historically-locked questions. Additionally, if you started a bounty on a historically-locked question before it got locked, you cannot award the bounty to any answer (because a historical lock will automatically lock the answers). Automatic awards are still possible, however.
What happens if I delete my account while I have an active bounty?
The bounty will just be moved to (owned by) the Community user and will be awarded automatically at the end of the period as they normally would. (source)
What happens to an awarded bounty if the awarded answer gets deleted?
In most cases, when an answer that received a bounty gets deleted, all reputation including the bounty are revoked. (This may take 5 minutes to be visible.) The bounty is not given back to the user who awarded it. (Exception: if the answer had a score of at least 3, and was visible for at least 60 days at the time of deletion, the bounty award is kept.)
Why can't I delete my own question where an answer has been awarded a bounty?
This was a recent change instituted on February 14, 2018. This is to prevent abuse, where the owner immediately deletes the question after the bounty is awarded. There have been cases where the answers involved have not received upvotes, or the questions have not received multiple answers, so such deletions have not been prevented by these ordinary measures.
What happens if a question where I awarded a bounty later gets deleted or migrated?
If a question on which you have started or awarded a bounty on later gets deleted, then in most cases, your reputation is refunded. It can take a few minutes for this to happen. If the question is later undeleted or migration is rejected, the reputation is deducted again. Source
There is one exception to the above rule, however: if the bounty was awarded to an answer, and the author gets to retain their reputation upon deletion (i.e. their answer earned a score of at least 3 and was visible for at least 60 days), the reputation is not refunded to the bounty starter. Source
If the question later gets migrated, the bounty remains attached to the migration stub and does not migrate. Note that the answers on the migration stub get deleted immediately upon migration, so the above rules apply in that case.
Can I cancel my bounty?
No. Once you start a bounty, you cannot cancel it.
If you feel there are exceptional circumstances, flag the question for moderator attention to explain the situation.
Can I affect / divide / share part of my bounty to two (or more) users?
No. If you feel that multiple answers deserve a bounty, start and award multiple bounties, one for each answer.
If multiple answers to a single question have earned bounties, it's because the question has been subject to multiple bounties.
How many outstanding bounties can a single user have?
Three. You must award a bounty after this point to start a new bounty.