Fool's Mate is the fastest checkmate possible in chess, and it occurs after only two moves! Don't worry, you can't be forced into this checkmate unless you make two bad moves in a row.
Here is Fool's mate in action:
In order the fool's mate to happen the g-pawn has to be moved up 2 squares and the f-pawns has to be moved up 1 square
Some of you may be wondering if this same mating pattern can be used with the white pieces, and the answer is "yes!" Black can lose in an identical fashion to Fool's Mate, but it takes an extra move. If Black moves their f-pawn up one or two squares and then moves their g-pawn up two squares, White can deliver checkmate on move three in what could be referred to as the "Reversed Fool's Mate":
Now I will show you the grob's attack (ALMOST LIKE THE FOOLS'S MATE, BUT WHITE JUST MOVES F4).