I play this whenever I go drinking. Someone from my chess club taught it to me years ago.
Take sixteen coins, organized like so:
X
XXX
XXXXX
XXXXXXX
You can take as many coins as you like from any single row at a time on your turn. The object of the game is to get your opponent to take the last coin. It’s a sophisticated tic tac toe that gives us something to go with our beers.
Confirmed: it’s Nim. And there is a trick to winning (which makes it a puzzle, not a game). Force your opponent into the no-win situation of two rows of two.
All games out of a very broad category have a trick to winning. Chess has a trick to winning. Go has a trick to winning. What makes Nim special is that the trick for winning it is known, and is simple enough that a human can apply it at any stage in the game.