The endgame rook and knight versus rook is quite rare. Nevertheless, it is very practical and the inexperienced player might easily succumb to the pressure.
Theoretically, it should be a draw, but there are huge dangers lurking if the king of the weak side finds itself blocked on the back rank. The most famous example of this happening was the game Polgar-Kasparov from Dos Hermanas 1996.
In that case the defender still has defensive ideas.
One of them was demonstrated in the game Ganguly-Yu from the World Rapid Championship: