The Fool's Mate
Moving the f- and g-pawns early opens the diagonal from h4 to the white king. It is the fastest possible checkmate.
Opening: Barnes Opening (1.f3). Set by Black. Level: Beginner.
Practise setting and escaping itThe moves
1.f3 e5 2.g4 Qh4#
It only works after a mistake
White must play g4 for it to work. Only works if White makes two weakening pawn moves. Any normal opening move avoids it.
How to avoid it
Develop normally, for example e4, d4 or Nc3, and keep the f- and g-pawns at home early on.