All versions of every page are saved in the wiki's database. As a result, it is easy to revert bad edits and return the article to a previous state.
Types of reversion
The simplest way to revert a bad edit is to undo it. The first step is to create a diff of the unwanted edit. This can be done in several ways:
- In Recent Changes, every edit has a "diff" link on the far left. Click this link.
- In the page history, every edit has an "undo" link on the far right. Click this link.
- In the page history, select any two revisions using the ratio buttons and press the "Compare selected revisions" button.
- The "cur" and "prev" links on the far left of each revision are shortcuts for "compare this revision with the current one" and "compare this revision with the previous one".
Once a diff page is ready, look above the right version of the text, where it reads "Latest revision as of <Date> (edit) (undo)". Click the "undo" link. Note that if you clicked the undo link in method 2 above, this step will be done for you.
At this point, you will be taken to the edit screen. The difference between the bad edit (left) and the previous revision (right) will be shown, and the edit summary field will contain an automatic message which you may choose to elaborate on. Should you save the page at this point, the edit will be undone; you may however make any changes you want (in which case you certainly should edit the automatic summary).
Note that it is not always possible to undo edits in this way if the two revisions are too different. For example, if edit 1 edits paragraph A and edit 2 edits paragraphs A and B, it may not be possible to only undo edit 1. In such cases, you will need to preform a manual reversion.
Rollback is a quick-undo of sorts. It automatically undoes the last edit done to a page, plus all consecutive edits made by that user to the page, without needing to load the page or an edit box. It cannot be previewed, its edit summary cannot be customized, and the user cannot make additional changes in the same edit.
As rollback is fully automatic and can be far more easily abused than other reversion options, users must demonstrate they understand its purpose before they are allowed to use it.
For more information on rollback, see SmashWiki:Rollback.
Reversion is more efficient at restoring a page to a previous verion if there have been several intervening edits. It requires a different method:
- Go to the page's history and click on the date of the desired revision. That revision will be displayed.
- Click on "edit this page" as usual. A notice will appear, warning you that you are editing an old version of the page.
If you simply save this edit, the page will be restored to the previous version. You may make changes to the text so the page is not identical to the old version.
If you choose to revert in this way, make sure to leave an edit summary explaining why you're doing it. Of the three methods on this page, reversion does not leave an automatic edit summary.
By its nature, reversion is a tool to restore articles to a previous state. As a result you should be able to explain why you think that an older version of the article was better.
- If the article was vandalised or something, simply saying "reverted vandalism" or similar in the edit summary is sufficient.
- If it is a matter of opinion, clearly state your reasoning in the edit summary. If there's not enough room, explain on the article's talk page.
Outside obvious vandalism and blatant misinformation, do not revert other users' reversions. This is called a revert war and is never a good thing. Discuss the issue on the talk page and come to a consensus instead of bulking up the database with several identical back-and-forth edits.
For more information, see SmashWiki:Edit warring.