Are there any common tactics or combinations used to beat complete beginners quickly (or gain large material advantages)?
By "beginner" I mean someone who is good enough not to get caught out by Scholar's mate, and knows basic opening principles, mate with king and rook etc., but not any actual openings.
As T.S. Eliot said, "There is no method but to be very intelligent." If the opponent is smart enough to avoid the known short mates and understands basic opening strategy, you'll just have to outplay them.
That said, in my experience, new players often miss forks, discovered attacks, and moves that theoretically place a piece under attack, but where the capture would result in a check or expose an attack on a more valuable piece. New players are often so focused on protecting the king and/or queen that they blunder away pawns and minor pieces by leaving them vulnerable to such moves.
My advice: play better than the beginner and you will rapidly overwhelm them and find blunders to exploit. :)Tweet