If you’re adding just a little well-sourced information to a page, or if you’re doing minor copyediting of a section of a page, then go ahead and do the edit; only rarely will someone object. But if you’re planning to add a lot of information, change a lot of wording, or reorganize an article, you can minimize content disputes if you do just a little bit of checking first: Read the article’s talk (discussion) page. If you see a gnarled mass of recent arguments, you stand a significant chance of getting caught up in an edit war. Even if you aren’t interested in joining whatever argument’s going on, other editors may interpret what you did as supporting one side or the other.

Secondly, you should routinely do a quick check in the article history tab. If you see a lot of recent edits, make sure you’re not updating a vandalized version.

Provide a good edit summary when making significant changes to which other users might object. If you can cite a relevant policy or guideline, do so. Wikilinks in edit summaries do work, as in this example:

Removing information that appears to be added from personal knowledge (see [[WP:NOR]]) and copyediting.

If you can’t fit your explanation into an edit summary, then put a brief summary and conclude it with See talk/discussion page. Explain further on the article talk page. (Chapter 8 covers the use of article talk pages—see Article Talk (Discussion) Pages.)

Reverts (Chapter 5) are powerful things. Use them only when there are clear policy violations. Experienced editors often consider being reverted an insult. (Consider how you’d feel if an edit you did that you thought improved an article was entirely removed.) If you revert an edit by an experienced editor, you’d better be justified.

It’s much better if you can salvage part of the content from an edit that you disagree with. And don’t use the rv expression or standard (software-supplied) undo text (4) in an edit summary unless you’re absolutely sure that you’re right. To quote directly from WP:DR: “When someone makes an edit you consider biased or inaccurate, improve the edit if you can, rather than reverting it, or if you do not see it as improvable, discuss it on the talk page.” (For more details on dealing with content added by others, see “Reviewing Content Changes: A General Plan of Action” on Reviewing Content Changes: A General Plan of Action.)

Wikipedia forbids edit wars—two or more editors reverting each other continuously. (For details, see Wikipedia:Edit war, shortcut WP:EW.) To prevent edit wars, the Wikipedia:Three-revert rule (shortcut: WP:3RR) states that editors who revert a page in whole or in part more than three times in 24 hours, except in certain special circumstances, are likely to be blocked from editing. Those exceptions include simple and obvious vandalism, copyright violations, spam, copyrighted images that lack a free content license, and unsourced or poorly sourced controversial material about living persons, particularly negative information, which could be libelous.

If you run into an editor who’s unaware of this policy, warn him after he’s done two or three reverts within a day to the same article, on the same content. You can find the standard warning at the page Template:uw-3rr. Simply post this warning text on the user talk page of the editor who’s approaching the 3RR limit (or has even gone over, but not yet been warned). If you want to use your own words, make sure to provide a wikilink to the policy Wikipedia:Three-revert rule, because you can’t expect new editors to find the policy without such a link.

Once you’ve posted the warning, don’t worry if the editor deletes it from his talk page. If an editor deletes the warning, that means he’s read it. The warning remains in the history of his user talk page. (Users have every right to delete postings from their own user talk page. Don’t make the mistake of taking it as an insult.)

The 3RR rule does not convey an entitlement to revert thrice each day, nor is it intended to encourage reverting as an editing technique. Rather, the rule acts as a sort of electric fence that gives a little leeway to revert but prevents an intense edit war. An administrator may still block an editor if her pattern of ongoing reverts is found to be disruptive, even if she’s following the 24-hour rule. The policy aims to get editors to work together; administrators consider it a violation when editors treat the rule like a challenge.

When disagreement about content spills over into incivility and personal attacks, it gets much harder to resolve the content dispute. Chapter 11 shows you how to deal with incivility and personal attacks directed against you, and also has advice on what to do if you get irritated (or worse) with another editor, or if you’ve posted something that you realize you shouldn’t have (If You Have Posted Something You Realize You Shouldn’t Have). If you’re involved in a disagreement over content that’s becoming uncivil, take a look at Chapter 11: If you can get the focus back to content, the chances are much better that you and other editors can find an acceptable compromise.

It’s a good idea, every now and then, to review the guideline at Wikipedia:Assume good faith (shortcut: WP:AGF). If you start out with the attitude that a particular editor is a problem, there’s a good chance that she will be one. On the other hand, if you assume that the editor is well-intentioned, but perhaps uninformed, and does have something to contribute, then you’re following the “assume good faith” guideline. You may be incorrect, but you won’t make the problem any worse.

Finally, it’s important to use article talk pages correctly. Keep discussions about editor behavior off article talk pages. Discussions about editors belong on user talk pages, not article talk pages. If someone else starts something on an article talk page, don’t take the bait.