Metagaming

Metagaming is when players write parts for their characters that the characters would not know (but the players do).

Players can acquire this knowledge either from reading previous posts or from reading the character's biography/character sheet. (Though if they create knowledge of other characters themselves this crosses over into power playing.)

This most commonly occurs when one player writes thoughts for their character but others have their characters respond to those thoughts like they were spoken.

Some of the major reasons that metagaming should be avoided are:

Metagaming breaks the In Character and Out of Character boundary. This makes others start to question just how much of the character is the writer. (Since some people like to insert parts of themselves into characters.)

This makes it so that characters can know things they shouldn't and can react in ways they normally wouldn't. People react differently when they know bits of information, even trivial things about others. Like if a couple knows someone (generally a close friend) doesn't like public displays of affection (ex- kissing or holding hands), they may tone down their affection even if otherwise they wouldn't.

Knowing larger secrets causes much more drastic changes in personality. For example (from popular TV series Dexter) if Debra Morgan knew her brother (Dexter Morgan) was a serial killer, that would affect her personality tremendously. She would be caught between turning him into the police (and betraying him) or saying nothing (and committing the felony of accessory to murder, among other crimes).

This change in behaviour is problematic when the character has no way to know that this other character has that secret.

Metagaming tends to cause hardships with other players. They generally don't like to play with others who are going to read their character's minds and/or react to things that were only ever thought.

So they may not make threads with the metagamer and if the metagamer join their threads, they may ignore power player's posts.

Staff may end up having to be called in to resolve situations since metagaming is usually against the rules of the forum. And no admin really wants to have to tell a member that they can't do something, it makes the admin feel like the villain. (Even if they're in the right in telling the member to behave.) Also, no member likes to be told that their behaviour is unacceptable. They may resent the admin for telling them to behave or at least feel like they're being unduly picked on.

Avoiding metagaming is easily done by re-reading posts before submitting them and constantly asking yourself: “How does my character know… <info>”. Then checking previous posts to see if a character actually stated or merely thought.

Information from biographies is a little more tricky since the character may not have talked about their history/past and that information may not be available to others. (Like in military situations where part of histories may be classified or removed if they were involved in covert operations.)

Many character sheets ask for weaknesses, but these probably won't be known. (Characters tend to keep their weaknesses hidden.) Though if they're a team then some weaknesses may be shared so that team members can help cover each other. (This would be part of effective teamwork. Though announcing weaknesses would not be a good idea, weaknesses should be an unstated but understood aspect.)

Similar to weaknesses, special attacks may also be listed but characters may not have used them or shown that they have them. So if you're not sure, it's generally a good idea to ask. (Which is a good policy for most things regarding other characters… If you're not sure, just ask.)

If a character has a valid (and plausible) reason for them to know some piece of information then it may not be metagaming. (Though they should mention how they know that bit of info.) For example, if a character is Psychic (like Charles Xavier of the X-men) then they would have the power to read minds, and if they so chose to… react like if thoughts were spoken. However most characters very likely won't be psychic (psychic powers may very well be restricted to prevent metagaming, powerplaying or godmodding).

Other things that characters do can also tell a lot about them. Things like keeping a journal or diary for their innermost thoughts or secrets can also allow others to know them if they read that book. (Though there should be some explanation of how/when they read that book and some care should be taken since this can easily cross over into powerplaying if not careful.) And other characters can learn from watching/spying on your character. (Though like with prying into their journal/diary, spying generally should have some in universe repercussions if/when discovered.)

Though in combat situations, characters may be able to gain information by observation and consideration. Like if an enemy uses fire magic they may have a weakness to water magic.