Metagaming is when you use knowledge that is not available to you in order to change the way you play your character (usually to give you an advantage within the game), such as knowledge of the mathematical nature of character statistics, or the statistics of a creature that the player is familiar with but the character has never encountered. In general, it refers to any gaps between player knowledge and character knowledge which the player acts upon.

Metagaming is when you use knowledge that is not available to you in order to change the way you play your character (usually to give you an advantage within the game), such as knowledge of the mathematical nature of character statistics, or the statistics of a creature that the player is familiar with but the character has never encountered. In general, it refers to any gaps between player knowledge and character knowledge which the player acts upon.