When game information outside of what is available in a game is used to give a player an advantage in-game. Most commonly seen and frowned upon in many forms of role playing especially when consent has not been given.
Example a.
A dungeons and dragons adventure team comes across an unknown monster in-game. The metagamer knows this monster through out-of-game information. Using this information, the metagamer's character acts upon the monster's weaknesses and attributes despite the character having never seen the monster before.
Example b.
In an online pan-fandom RPG, Ryoga from Ranma 1/2 meets Ken from Street Fighter for the first time and they have a fight to the death. Ken finds some water in a random nearby bucket and dumps it on Ryoga, then proceeds to pummel the life out of Ryoga who is now transformed into a tiny black pig because of his water curse.
The highest level of strategy in many complex games, metagame refers to any aspect of strategy that involves thinking about what your opponent is thinking you are thinking.
Metagame comes into play in any game where no single strategy is dominant and opposing sides are aware of multiple strategies that can succeed dependent upon opponents' actions. In order to perform at the highest level, it then becomes necessary to think about what your opponent thinks you will do (which may depend on what he thinks you think he thinks he will do, etc.) and to make decisions based on clues regarding what level they are thinking on.
This term is most commonly used to refer to poker and other complex card games, but is increasingly being used in relation to video games with complicated playervsplayer elements and even traditional sports.
Normally I would raise the flop with this hand as a semi-bluff, but I've been so aggressive lately that taking metagame into consideration I think he will go all-in with any pair, so instead I'm going to fold.
This guy thinks that I'm going to zergling rush which means he will waste resources defending early. Instead I am going to focus on resource development for mid game, and metagame will win me this match.
An orgasm derived from listening to music of the metal genre. Usually occurs during screaming/growling parts of a song and will result in goosebumps and a smile.
Girl: Have you ever listened to Otep?
Boy: No, why are they awesome?
Girl: Awesome...yeah...so awesome I got a metalgasm the first time I listened to them.
Boy: ...
Girl: It was almost better than a real orgasm.
Boy: Wait...What?
The act of using outside or previously gained knowledge within a gaming universe for personal gain or advantage.
John was accused of metagaming when he immediately moved his player to the most protected area of the map to snipe the enemy team members, since he had played the map before and knew from experience.