I think one of the things people take for granted about games in general is that they are by nature social activities. Often, that is not their purpose. Games can be played for honor (think Sporting Events) or money (Card Sharks at a poker table), or any other number of different purposes.
Coming to the point, a "friendly game" is one that is competitive, but not played for any wager to be settled. No betting. You play until someone wins for the fun of it. You try to beat the other player. You are unconcerned about your overall score or how many wins and losses occur between you, you simply have chosen to compete with them in order to spend time with them and learn something about their behavior. Perhaps you both simply enjoy the game in question. The point is, you aren't actually losing or winning anything except time and relief from your boredom, respectively.
Now, I would ask anyone who considers themselves a "gamer" to consider the question, what constitutes a friendly game to you? What does it look like? Feel like? Do you have any snacks? Should you have snacks? What kinds of rules are there, both general and game-specific?
Describe what it's like playing video games with your friends.
Why, you ask?
No real reason other than it's been years and years since I did that. I played Streets of Rage 2 with my relatively new girlfriend the other day. She picked Max and utterly wrecked shit at it. She liked it. We had a good time. I had forgotten how nice it was to have someone around to play with.