are you allowed to play in a game with a friend/roommate? I was just in a game with two guys who were roommates and allied. Seems unfair....

No reason why you can't as long as they abide by the "no deals longer than a game" rule - if they start trading off games (aka I'll help you in this one you help me in that one) then that is against the rules and ethics of the game.

Yeah, it's definitely not "fair." But that's the spirit of the game! Getting unfair advantages, haha.
But lets be honest: the most fun would be to stab your friend in the back

Yeah but how do you follow any of that? You have to assume there is always some kind of conscious or unconscious biases. They could also be blatantly sharing info/showing screens.

If a player plays with 2 friends, with a bunch of random players, would it not be possible for them to affect the outcome of every game they play together, thus essentially guaranteeing a medal every time. If they rotate who wins each game, this might allow players to manipulate the ratings system.

I'm playing a game against one of my housemates, just a 1v1 so he can get a feel of the game. When/if we meet up in a public game, it's more than likely that he'd be my first target. I guess some people are nicer to their friends than I am.

Whats the difference between two players sharing a room and always joining the same game and two players that met ingame and and always join the same game? Everything you share with your roommate offline you can share with that other player via the chat.

It's a premise agreement. And they can share screens.

There is nothing you can see on screen that you can't communicate via chat.

And sorry, I'm not a native speaker, what is a premise agreement?

kinc4id wrote:There is nothing you can see on screen that you can't communicate via chat.

Yes, but it requires that the friend ask.
If you're showing someone your screen, they can glean more information than what you're telling them.