Metagame, meta for short, is simply a term that refers to what you expect people to do based on what people tend to do, generally because the thing they're doing is good at winning. It's the reason "anti-meta" decks use Fossil Dyna Pachycephalo.
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[img]http://vignette1.wikia.nocookie.net/yugioh/images/a/ae/FossilDynaPachycephalo-AP04-EN-C-UE.png/revision/latest/scale-to-width-down/300?cb=20140406104936[/img]
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I don't intend to use meta decks, (or even 3 Pots) as they're not very fun imo, (or in the case of excessive pots, will simply feel broken) especially in an RP environment. That being said, 3 Pot of Greeds would* be part of "the meta" simply because Pot of Greed is a broken card. (*though from [i]glancing[/i] at the character apps, it doesn't seem to be) and because of that, the card Mystic Piper, which provides the same draw power but with a requirement (top-decking a level one monster) and cost, (of summoning it) probably wouldn't be able to justify its place in a deck.
[hider=Mystic Piper, in case you're unfamiliar with the card.]
[img]http://vignette3.wikia.nocookie.net/yugioh/images/f/ff/MysticPiper-EXVC-EN-ScR-1E.jpg/revision/latest/scale-to-width-down/300?cb=20110819212049[/img]
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