There's more then one type of "meta gaming".
There's the black and white kind that's blatantly against the rules, and these include things like:
- You and your roommate player in a game together and teaming up
- Making cross game deals (help me here and i'll help you over there)
- Joining a game with a preconceived arrangement or intent ("i only want to go in and sabotage that guys game because he stabbed me in our last game" or "i always end up 2wd'ing with Jonnie when we play, he'll totally do it again because we like each other")
But then there's also implied rules in place that sounds great in theory but tend to bump against human nature a little bit...
- Don't allow personal biases or past history to affect your game
- No referring to past games in a current game
Do we all try our best to turn off past experiences every time we walk into a game? We want to, we mean to. We know how a person played in one game isn't necessarily the same approach they'll take in this game. Everybody deserve a clean slate while past experience, personal knowledge, past emotions, and all that available information ought have no bearing.
Realistic? Not particularly, at least not once you've been around for a while.
I freely admit on occasion I've let past games bias my judgement on wanting to not ally with players due to past headaches caused by personality conflict. I've specifically sought out games with strong players i want to challenge myself to beat. I've had reluctance to put trust in players with very high solo rates and I've been drawn to ally with players with high draw rates assuming them more loyal. I've research players to study their strategy, loyalty, temperament based on public press, and level of competition. It's not easy to choose to ignore knowledge. Try being a top ranker and expect to be treated like every other player in a public game, there's a reason we often choose to play anonymous game.
At the end of the day it's a relatively small community of active players with a good deal of accessible history and personally i really love this dynamic of this site. I like that players have to take into consideration their reputation beyond a single match-up, i find it an extremely interesting twist. History matters here and it impacts how you have to approach the game. I enjoy the homework aspect of preparing strategy and i highly respect for those who do homework when playing against me, it elevates the game and forces you to constantly evolve.
Am i saying meta-gaming is a concept too abstract to govern? Emphatically not, there's absolutely lines not to be crossed. Do homework, just don't use history as an in-game influence on others ("hey, check out game #... you can see that dude is a proven liar). Have opinions on players, but try to keep an open mind in new games anyways (more fun that way anyways). Try not to hold onto grudges (good life philosophy as well). And really it's just a good rule of thumb to try to avoid games blending together, I generally pass on "rematch" games or requests from players i just played to participate in a new game just starting. A little distance of time goes a long way in keeping games fairly separate in your head.