The Three-revert rule (or 3RR) is an official policy which applies to all editors. The policy states that an editor must not perform more than three reversions on a single public article (that is, which is free for all editors to edit) of the HP Fanon Wiki within 24 hours of their first reversion. (This does not apply to self-reverts or correction of simple vandalism). This does not imply that reverting three times or less is acceptable. In excessive cases, people can be blocked for edit warring or disruption even if they do not revert more than three times per day.
Using sockpuppets (multiple accounts) is not a legitimate way to avoid this limit, and the policy specifically does not apply to groups. Any reversions beyond this limit should be performed by somebody else, to serve the vital purpose of showing that the community at large is in agreement over which of two competing versions is correct.
Detail
Before exceeding the three reversion limit, please discuss the matter with other editors whom you respect. If any of these editors become at risk of breaching the policy themselves, this indicates that the relevant page should be protected until such time as any disputes are resolved.
The policy is independently applied to each page; reversions are not counted cumulatively across multiple pages. For example, if an editor performs three reversions on each of two articles within 24 hours, that editor's six reversions do not constitute a violation of this policy.
This policy does not apply to self-reverts, correcting simple vandalism, or reversions for the purpose of maintenance. Also, as stated before, it does not apply to personal universe articles as well.
This policy does apply to repeatedly moving, renaming, deleting, undeleting, or recreating a page. All of those, if done excessively, are forms of edit warring.
Reverting doesn't only mean taking a previous version from history and editing that. It means undoing the actions of another editor, and may include edits that mostly undo a previous edit and also add something new, page moving, admin actions such as protection, etc. Use common sense.
Intent of the policy
The three-revert rule is not an entitlement, but an "electric fence"; the 3RR is intended to stop edit wars. It does not grant users an inalienable right to three reverts every 24 hours or endorse reverts as an editing technique. Persistent reversion remains strongly discouraged and is unlikely to constitute working properly with others.
If you find you have reverted a page more than even once in a day, it indicates there is a serious problem and you should try dispute resolution, starting with the article's talk page.
The fact that users may be blocked for excessive reverting does not imply that they will be blocked. The admins are under no obligation to block a user for breaking the 3RR, for instance if they see that the problem has been resolved in another manner.