A: If a rated game ends with fewer than 3 moves made (so called "short game"), it will not affect your rating, and will be treated as an unrated game. The reason being, it's hardly possible to show that someone was winning or losing a game after only 2 moves.
Please note however, that short games still affect tournament results, team match results, etc., and only the rating will be unchanged. Also, please note, that in chess moves are counted in pairs — i.e. 3 moves means
both opponents made 3 moves each.
» More about the
rating system.